XC2100A-20 ANAREN | Alldatasheet

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Place Manufacturing. USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Model XC2100A-20 Rev D t 20 dB Directional Coupler

Description

The XC2100A-20 is a low profile, high performance 20dB directional coupler in a new easy to use, manufacturing friendly surface mount package. It is designed for UMTS and other 3G applications. The XC2100A-20 is designed particularly for power and frequency detection, as well as for VSWR monitoring, where tightly controlled coupling and low insertion loss is required. It can be used in high power applications up to 150 Watts. Parts have been subjected to rigorous qualification testing and they are manufactured using materials with coefficients of thermal expansion (CTE) compatible with common substrates such as FR4, G-10, RF-35, RO4350, and polyimide. Available in both 5 of 6 tin lead (XC2100A-20P) and 6 of 6 tin immersion (XC2100A-20S) RoHS compliant finishes. Electrical Specifications Frequency Mean Coupling Insertion Loss VSWR Directivity MHz dB dB Max Max : 1 dB Min 2000-2300 20.1 ± 0.60 0.15 1.15 23 2110-2170 20.0 ± 0.50 0.12 1.12 25 Frequency Sensitivity Power ΘJC Operating Temp. dB Max Avg. CW Watts ºC/Watt ºC ± 0.12 120 25 -55 to +95 ± 0.05 150 25 -55 to +95 Features:

  • 2000 – 2300 MHz
  • UMTS and other 3G
  • High Power
  • Very Low Loss
  • Tight Coupling
  • High Directivity
  • Production Friendly
  • Tape and Reel
  • Available in Lead-Free (as illustrated) or Tin-Lead
  • Reliable, FIT=0.41 **Specification based on performance of unit properly in stalled on Anaren Test Board 54606-0003 with small signal applied. Specifications subject to change without notice. Refer to parameter definitions for details. XC2100A-20* Mechanical Outline Dimensions are in Inches [Millimeters] Side View .060±.120 [1.52±3.05] Bottom View (Far-Side)Top View (Near-Side) Denotes Array Number 4X .040±.004 [1.02±0.10] 4X .059±.004 SQ [1.50±0.10] .430±.004 [10.92±0.10] .220±.004 [5.59±0.10] GND GND Pin 1 Pin 2 Pin 3Pin 4 Pin 1Pin 2 Pin 4Pin 3 .560±.010 [14.22±0.25] .350±.010 [8.89±0.25] Orientation Marker Denotes Pin 1 *For RoHS Compliant Versions order with S suffix Tolerances are Non-Cumulative

USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Available on Tape and Reel for Pick and Place Manufacturing. Model XC2100A-20 Rev D Directional Coupler Pin Configuration The XC2100A-20 has an orientation marker to denote Pin 1. Once port one has been identified the other ports are known automatically. Please see the chart below for clarification: 20dB Coupler Pin Configuration Pin 1 Pin 2 Pin 3 Pin 4 Input Direct Isolated Coupled Direct Input Coupled Isolated Note: The direct port has a DC connection to the input port and the coupled port has a DC connection to the isolated port. For optimum performance use Pin 1 or Pin 2 as inputs.

Place Manufacturing. USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Model XC2100A-20 Rev D Insertion Loss and Power Derating Curves Insertion Loss Derating: The insertion loss, at a given frequency, of a group of couplers is measured at 25 °C and then averaged. The measurements are performed under small signal conditions (i.e. using a Vector Network Analyzer). The process is repeated at 95°C, 150°C, and 200°C. A best- fit line for the measured data is computed and then plotted from -55°C to 300°C. Power Derating: The power handling and corresponding power derating plots are a function of the thermal resistance, mounting surface temperature (base plate temperature), maximum continuous operating temperature of the coupler, and the thermal insertion loss. The thermal insertion loss is defined in the Power Handling section of the data sheet. As the mounting interface temperature approaches the maximum continuous operating temperature, the power handling decreases to zero. 0 25 50 75 100 125 150 175 200 225 250 275 300 100 125 150 175 200 225 Base Plate Temperature (ºC) P ow er (W atts ) Power Derating Curve for XC2100A-20 power handling at 2170MHz power handling at 2300MHz -100 -50 0 50 100 150 200 250 300 350 -0.2 -0.18 -0.16 -0.14 -0.12 -0.1 -0.08 -0.06 -0.04 -0.02 Temperature of the Part (ºC) Insertion Loss (dB) Typical Insertion Loss Derating Curve for XC2100A-20 typical insertion loss (f=2170MHz) typical insertion loss (f=2300MHz)

USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Available on Tape and Reel for Pick and Place Manufacturing. Model XC2100A-20 Rev D Typical Performance (-55°C, 25°C and 95°C): 2000-2300 MHz 2000 2050 2100 2150 2200 2250 2300 -50 -45 -40 -35 -30 -25 -20 -15 -10 Frequency (MHz) R eturn Los s (dB ) Return Loss for XC2100A-20 (Feeding Port 1) - 55ºC 25ºC 95ºC 2000 2050 2100 2150 2200 2250 2300 -50 -45 -40 -35 -30 -25 -20 -15 -10 Frequency (MHz) R eturn Los s (dB ) Return Loss for XC2100A-20 (Feeding Port 2) - 55ºC 25ºC 95ºC 2000 2050 2100 2150 2200 2250 2300 -50 -45 -40 -35 -30 -25 -20 -15 -10 Frequency (MHz) R eturn Los s (dB ) Return Loss for XC2100A-20 (Feeding Port 3) - 55ºC 25ºC 95ºC 2000 2050 2100 2150 2200 2250 2300 -50 -45 -40 -35 -30 -25 -20 -15 -10 Frequency (MHz) R eturn Los s (dB ) Return Loss for XC2100A-20 (Feeding Port 4) - 55ºC 25ºC 95ºC

Place Manufacturing. USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Model XC2100A-20 Rev D Typical Performance (-55°C, 25°C and 95°C): 2000-2300 MHz 2000 2050 2100 2150 2200 2250 2300 -21 -20.8 -20.6 -20.4 -20.2 -20 -19.8 -19.6 -19.4 -19.2 -19 Frequency (MHz) Coupling (dB) Coupling for XC2100A-20 (Feeding Port 1) - 55ºC 25ºC 95ºC 2000 2050 2100 2150 2200 2250 2300 -0.2 -0.18 -0.16 -0.14 -0.12 -0.1 -0.08 -0.06 -0.04 -0.02 Frequency (MHz) Insertion Loss (dB) Insertion Loss for XC2100A-20 (Feeding Port 1) - 55ºC 25ºC 95ºC 2000 2050 2100 2150 2200 2250 2300 -0.2 -0.18 -0.16 -0.14 -0.12 -0.1 -0.08 -0.06 -0.04 -0.02 Frequency (MHz) Transm ission Loss (dB) Transmission Loss for XC2100A-20 (Feeding Port 1) - 55ºC 25ºC 95ºC 2000 2050 2100 2150 2200 2250 2300 -50 -45 -40 -35 -30 -25 -20 -15 -10 Frequency (MHz) D irec tiv ity (dB ) Directivity for XC2100A-20 (Feeding Port 1) - 55ºC 25ºC 95ºC

USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Available on Tape and Reel for Pick and Place Manufacturing. Model XC2100A-20 Rev D Definition of Measured Specifications Parameter Definition Mathematical Representation VSWR (Voltage Standing Wave Ratio) The impedance match of the coupler to a 50Ω system. A VSWR of 1:1 is optimal. VSWR = min max V V Vmax = voltage maxima of a standing wave Vmin = voltage minima of a standing wave Return Loss The impedance match of the coupler to a 50Ω system. Return Loss is an alternate means to express VSWR. Return Loss (dB)= 20log 1-VSWR 1VSWR + Mean Coupling At a given frequency (ωn), coupling is the input power divided by the power at the coupled port. Mean coupling is the average value of the coupling values in the band. N is the number of frequencies in the band. Coupling (dB) = ⎟⎟ = )( )(log10)( ncpl nin n P PC ω ωω Mean Coupling (dB) = N C N n )(ω Insertion Loss The input power divided by the sum of the power at the two output ports. 10log direct cpl in PP P Transmission Loss The input power divided by the power at the direct port. 10log direct in P P Directivity The power at the coupled port divided by the power at the isolated port. 10log iso cpl P P Frequency Sensitivity The decibel difference between the maximum in band coupling value and the mean coupling, and the decibel difference between the minimum in band coupling value and the mean coupling. Max Coupling (dB) – Mean Coupling (dB) and Min Coupling (dB) – Mean Coupling (dB)

Place Manufacturing. USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Model XC2100A-20 Rev D Notes on RF Testing and Circuit Layout The XC2100A-20 Surface Mount Couplers require the use of a test fixture for verification of RF performance. This test fixture is designed to evaluate the coupler in the same environment that is recommended for installation. Enclosed inside the test fixture, is a circuit board that is fabric ated using the recommended footprint. The part being tested is placed into the test fixture and pressure is applied to the top of the device using a pneumatic piston. A four port Vector Network Analyzer is connected to the fixture and is used to measure the S-parameters of the part. Worst case values for each parameter are found and compared to the specificat ion. These worst case values are reported to the test equipment operator along with a Pass or Fail flag. See the illustrations below. 3 & 5 dB Test Board 10 & 20 dB Test Board Test Board In Fixture Test Station

USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Available on Tape and Reel for Pick and Place Manufacturing. Model XC2100A-20 Rev D The effects of the test fixture on the measured data must be minimized in order to accurately determine the performance of the device under test. If t he line impedance is anything other than 50 Ω and/or there is a discontinuity at the microstrip to SMA interface, there will be errors in the data for the device under test. The test environment can never be “perfect”, but the procedure used to build and evaluate the te st boards (outlined below) demonstrates an attempt to minimize the errors associated with testi ng these devices. The lower the signal level that is being measured, the more impact the fixtur e errors will have on the data. Para meters such as Return Loss and Isolation/Directivity, which are specifi ed as low as 27dB and typically measure at much lower levels, will present the greatest measurement challenge. The test fixture errors introduce an uncertainty to the meas ured data. Fixture errors can make the performance of the device under test look better or worse than it actually is. For example, if a device has a known return loss of 30dB and a discontinuity with a magnitude of –35dB is introduced in to the measurement path, t he new measured Return Loss data could read anywhere between –26dB and –37dB. This sa me discontinuity could introduce an insertion phase error of up to 1°. There are different techniques used throughout the industr y to minimize the affects of the test fixture on the measurement data. Anaren uses the following design and de-embedding criteria:

  • Test boards have been designed and parameters s pecified to provide trace impedances of 50 ±1Ω. Furthermore, discontinuities at the SMA to micr ostrip interface are required to be less than –35dB and insertion phase errors (due to differenc es in the connector interface discontinuities and the electrical line length) should be less than ±0.25° from the median value of the four paths.
  • A “Thru” circuit board is built. This is a two po rt, microstrip board that uses the same SMA to microstrip interface and has the same total length (insertion phase) as the actual test board. The “Thru” board must meet the same stringent re quirements as the test board. The insertion loss and insertion phase of the “Thru” board are measured and stored. This data is used to completely de-embed the device under test fr om the test fixture. The de-embedded data is available in S-parameter form on the Anaren website (www.anaren.com). Note: The S-parameter files that are available on the ana ren.com website include data for frequencies that are outside of the specified band. It is impor tant to note that the test fixture is designed for optimum performance through 2.3GHz. Some degradation in the test fixture performanc e will occur above this frequency and connector interface discontinuities of –25dB or more can be expected. This larger di scontinuity will affect the data at frequencies above 2.3GHz. Circuit Board Layout The dimensions for the Anaren test board are shown below. The test board is printed on Rogers RO4350 material that is 0.030” thick. Consider the case when a different material is us ed. First, the pad size must remain the same to accommodate the part. But, if the material thickness or diel ectric constant (or both) ch anges, the reactance at the interface to the coupler will also change. Second, the linewidth required for 50Ω will be different and this will introduce a step in the line at the pad where the coupler interfaces with the printed microstrip trace. Both of these conditions will affect the performance of the part. To achieve the specified performance, serious attention must be given to the design and layout of the circuit environment in which this component will be used. If a different circuit board material is used, an attempt should be made to achieve the same interface pad reactance that is present on the Anaren RO4350 test board. When thi nner circuit board material is used, the ground plane will be closer to the pad yielding more capacitance for the same size interface pad. The same is true if the dielectric constant of the circuit board material is higher than is used on the Anaren test board. In both of these cases,

Place Manufacturing. USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Model XC2100A-20 Rev D narrowing the line before the interface pad will introduce a series inductance, which, when properly tuned, will compensate for the extra capacitive reactance. If a thicker circuit board or one with a lower dielectric constant is used, the interface pad will have less capacitive reactance than the Anaren test board. In this case, a wider section of line before the interface pad (or a larger interface pad) will in troduce a shunt capacitance and when properly tuned will match the performance of the Anaren test board. Notice that the board layout for the 3dB and 5dB couplers is different from that of the 10dB and 20dB couplers. The test board for the 3dB and 5dB couplers has all four traces interfacing with the coupler at the same angle. The test board for the 10dB and 20dB couplers has two traces approaching at one angle and the other two traces at a different angle. The entry angle of the traces has a significant impact on the RF performance and these parts have been optimized for the layout used on the test boards shown below. 10 & 20dB Test Board 3 & 5dB Test Board Testing Sample Parts Supplied on Anaren Test Boards If you have received a coupler installed on an Anaren produced microstrip test board, please remember to remove the loss of the test board from the measured data. The loss is small enough that it is not of concern for Return Loss and Isolation/Directivity, but it should ce rtainly be considered when measuring coup ling and calculating the insertion loss of the coupler. An S-parameter file for a “Thru” board (see description of “Thru” board above) will be supplied upon request. As a first order approximation, one should consider the following loss estimates: Frequency Band Avg. Ins. Loss of Test Board @ 25°C 800 – 1000 MHz ~ 0.07dB 1700 – 2300 MHz ~ 0.12dB For example, a 1900MHz, 10dB coupler on a test board may measure –10.30dB from input to the coupled port at some frequency, F1. When the loss of the test board is removed, the coupling at F1 becomes -10.18dB (-10.30dB + 0.12dB). This compensation must be made to both the c oupled and direct path measurements when calculating insertion loss. The loss estimates in the table above come from room temp erature measurements. It is important to note that the loss of the test board will change with temperature. This fact must be considered if the coupler is to be evaluated at other temperatures.

USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Available on Tape and Reel for Pick and Place Manufacturing. Model XC2100A-20 Rev D Peak Power Handling High-Pot testing of these couplers during the qualification procedure result ed in a minimum breakdown voltage of 1.7KV (minimum recorded value). This voltage level corres ponds to a breakdown resistance capable of handling at least 12dB peaks over average power levels, for very shor t durations. The breakdown location consistently occurred across the air interface at the coupler contact pads (see illu stration below). The breakdown levels at these points will be affected by any contamination in the gap area around th ese pads. These areas must be kept clean for optimum performance. It is recommended that the user test for voltage breakdown under the maximum operating conditions and over worst case modulation induced power peaking. This evaluation should also include extreme environmental conditions (such as high humidity). Orientation Marker A printed circular feature appears on t he top surface of the coupler to designate Pin 1. This orientation marker is not intended to limit the use of the symmetry that these couplers exhibit but rather to facilitate consistent placement of these parts into the tape and reel package. This ensures that the components are always delivered with the same orientation. Refer to the table on page 2 of the data sheet for allowable pin configurations. Test Plan Xinger II couplers are manufactured in large panels and then separated. A sample population of parts is RF small signal tested at room temperature in the fixture described above. All parts are DC tested for shorts/opens. (See “Qualification Flow Chart” section for details on the accelerated life test procedures.)

Place Manufacturing. USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Model XC2100A-20 Rev D Power Handling The average power handling (total input power) of a Xinger coupler is a function of:

  • Internal circuit temperature.
  • Unit mounting interface temperature.
  • Unit thermal resistance
  • Power dissipated within the unit. All thermal calculations are based on the following assumptions:
  • The unit has reached a steady state operating condition.
  • Maximum mounting interface temperature is 95 oC.
  • Conduction Heat Transfer through the mounting interface.
  • No Convection Heat Transfer.
  • No Radiation Heat Transfer.
  • The material properties are constant over the operating temperature range. Finite element simulations are made for each unit. T he simulation results are used to calculate the unit thermal resistance. The finite element simulation requires the following inputs:
  • Unit material stack-up.
  • Material properties.
  • Circuit geometry.
  • Mounting interface temperature.
  • Thermal load (dissipated power). The classical definition for dissip ated power is temperature delta ( ΔT) divided by thermal resistance (R). The dissipated power (Pdis) can also be calculated as a function of the total input power (Pin) and the thermal insertion loss (ILtherm): )(101 10 WPR TP thermIL indis ⎟⎟ ⎛ −⋅=Δ= (1) Power flow and nomenclature for an “H” style coupler is shown in Figure 1.

USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Available on Tape and Reel for Pick and Place Manufacturing. Model XC2100A-20 Rev D Pin 1 Pin 4 Input Port Coupled Port Isolated Port Direct Port PIn POut(RL) POut(DC) POut(CPL) POut(ISO) Figure 1 The coupler is excited at the input port with Pin (watts) of power. Assuming the coupler is not ideal, and that there are no radiation losses, power will exit the coupler at all four port s. Symbolically written, P out(RL) is the power that is returned to the source because of impedance mismatch, P out(ISO) is the power at the isolated port, P out(CPL) is the power at the coupled port, and Pout(DC) is the power at the direct port. At Anaren, insertion loss is defined as the log of the input power divided by the sum of the power at the coupled and direct ports: Note: in this document, insertion loss is taken to be a positi ve number. In many places, insertion loss is written as a negative number. Obviously, a mere sign change equates the two quantities. )dB(PP Plog10IL )DC(out)CPL(out in 10 ⎟⎟ +⋅= (2) In terms of S-parameters, IL can be computed as follows: )dB(SSlog10IL 3110 ⎟⎠ ⎞⎜⎝ ⎛ +⋅−= (3) We notice that this insertion loss value includes the power lost because of return loss as well as power lost to the isolated port. For thermal calculations, we are only interested in the power lost “inside” the coupler. Since P out(RL) is lost in the source termination and P out(ISO) is lost in an external termination, they are not be included in the insertion loss for thermal calculations. Therefore, we define a new insertion loss value solely to be used for thermal calculations:

Place Manufacturing. USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Model XC2100A-20 Rev D )(log10 )()()()( 10 dBPPPP PIL RLoutISOoutDCoutCPLout in therm ⎟⎟ +++⋅= (4) In terms of S-parameters, ILtherm can be computed as follows: )(log10 1110 dBSSSSILtherm ⎟⎠ ⎞⎜⎝ ⎛ +++⋅−= (5) The thermal resistance and power dissipated within the unit are then used to calculate the average total input power of the unit. The average total steady state input power (Pin) therefore is: 101101 1010 WR T PP thermtherm ILIL dis in ⎛ − Δ ⎛ − = −− (6) Where the temperature delta is the circuit temperature (Tcirc) minus the mounting interface temperature (Tmnt): )( CTTT o mntcirc −=Δ (7) The maximum allowable circuit temperature is defined by the properties of the materials used to construct the unit. Multiple material combinations and bonding techniques are used within the Xinger II product family to optimize RF performance. Consequently the maximum allowable circui t temperature varies. Please note that the circuit temperature is not a function of the Xinger case (top surf ace) temperature. Therefore, the case temperature cannot be used as a boundary condition for power handling calculations. Due to the numerous board materials and mounting configuratio ns used in specific customer configurations, it is the end users responsibility to ensure that the Xinger II coupler mounting interface temperature is maintained within the limits defined on the power derating plots for the required average power handling. Additionally appropriate solder composition is required to prevent reflow or fatigue failure at the RF ports. Finally, reliability is improved when the mounting interface and RF port temperatures are kept to a minimum. The power-derating curve illustra tes how changes in the mounting interface temper ature result in converse changes of the power handling of the coupler.

USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Available on Tape and Reel for Pick and Place Manufacturing. Model XC2100A-20 Rev D Mounting In order for Xinger surface mount couplers to work optimally, there must be 50 Ω transmission lines leading to and from all of the RF ports. Also, there must be a very good ground plane underneath the part to ensure proper electrical performance. If either of these two conditions is not satisfied, insertion loss, coupling, VSWR and isolation may not meet published specifications. Overall ground is improved if a dense population of plated through holes connect the top and bottom ground layers of the PCB. This minimizes ground inductance and improves ground continuity. All of the Xinger hybrid and directional couplers are constructed from ceramic filled PTFE composites which possess excellent electrical and mechanical stability having X and Y thermal coefficient of expansion (CTE) of 17-25 ppm/ oC. When a surface mount hybrid coupler is mounted to a printed circuit board, the prim ary concerns are; ensuring the RF pads of the device are in contact with the circuit trace of the PCB and insuring the ground plane of neither the component nor the PCB is in contact with the RF signal. Mounting Footprint To ensure proper electrical and thermal performance there must be a ground plane with 100% solder connection underneath the part Dimensions are in Inches [Millimeters] XC2100A-20* Mounting Footprint .220 [5.59] 4X .066 SQ [1.65] 4X 50 Ω Transmission Line 4X .040 [1.02] Multiple plated thru holes to ground .430 [10.92] Coupler Mounting Process The process for assembling this component is a conventional surface mount process as shown in Figure 1. This process is conducive to both low and high volume usage. Figure 1: Surface Mounting Process Steps Storage of Components: The Xinger II products are available in either an immersion tin or tin-lead finish. Commonly used storage procedures used to control oxidation should be followed for these surface mount components. The storage temperatures should be held between 15 O C and 60 O Substrate: Depending upon the particular component, the circuit material has an x and y coefficient of thermal expansion of between 17 and 25 ppm/°C. This coefficient minimizes solder joint stresses due to similar expansion rates of most commonly used board substrates such as RF35, RO4350, FR4, polyimide and G-10 materials. Mounting to “hard” substrates (alumina etc.) is possible depending upon operational temperature requirements. The solder surfaces of the coupler are all copper plated with either an immersion tin or tin-lead exterior finish. Solder Paste: All conventional solder paste formulations will work well with Anaren’s Xinger II surface mount components. Solder paste can be applied with stencils or syringe dispensers. An exam ple of a stenciled solder paste deposit is shown in Figure 2. As shown in the figure solder paste is applied to the four RF pads and the entire ground plane underneath the body of the part.

Place Manufacturing. USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Model XC2100A-20 Rev D Qualification Flow Chart

USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Available on Tape and Reel for Pick and Place Manufacturing. Model XC2100A-20 Rev D

Place Manufacturing. USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Model XC2100A-20 Rev D

Application Information

Directional Couplers and Sampling Directional couplers are often used in circuits that requi re the sampling of an arbitrary signal. Because they are passive, non-linear devices, Anaren directional couplers do not perturb the characteristics of the signal to be sampled, and can be used for frequency monitoring and/or measurement of RF power. An example of a sampling circuit is the reflectometer. The purpose of the reflectometer is to isolate and sample the incident and reflected signals from a mismatched load. A basic reflectometer circuit is shown in Figure ap.n.1-1. Figure ap.n.1-1. A Reflectometer Circuit Schematic If the directional coupler has perfect di rectivity, then it is clear that V I is strictly a sample of the incident voltage V input, and VR is strictly a sample of the wave that is reflected from the load. Since directivity is never perfect in practice, both VI and VR will contain samples of the input signal as well as the reflected signal. In that case, θj I eV Γ+= CDTC Eq. ap.n.1-1 and φj R eV Γ+= CTCD Eq. ap.n.1-2 where C is the coupling, D is the directivity, Γ is the complex reflection coefficient of the load, T is the transmission coefficient, and φ and θ are unknown phase delay differences caused by the interconnect lines on the test board. If we know VI and VR, we can easily calculate the reflection coefficient of the load. One should notice that in order to make forward and reverse measurements using only one coupler, th e directivity must be really lo w. In specific customer applications, the preferred method for forward and reverse sampling is shown in Figure ap.n.1-2. LOAD Reflected Wave Vinput IVV R

USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Available on Tape and Reel for Pick and Place Manufacturing. Model XC2100A-20 Rev D LOAD Reflected Wave INPUT ISOLATOR REVERSE MEASUREMENT MEASUREMENT FORWARD RFP-500500A6Z50150 RFP-375375A6Z5050 RFP-250375A4Z5015 RFP-060120A15Z508 MODELPower (Watts) RECOMMENDED TERMINATIONS TERMINATION Figure ap.n.1-2. Forward and Reverse Sampling The isolator in Figure ap.n.1-2 prevents the reflected wave from exciting the directional coupler. A list of recommended terminations is shown in the figure. Directional Couplers in Feed-Forward Amplifier Applications Feed-forward amplifiers are widely used to reduce distortion due to nonlinearities in power amplifiers. Although the level and complexity of feed-forward amplifiers varies from one manufacturer to another, the basic building block for this linearization scheme remains the same. A basic feed-forward sc hematic is shown in Figure ap.n.2-1. The input signal is split in two using a hybrid coupler or power divider. The output of the main amplifier is sampled with a 20dB-30dB directional coupler. The XC2100A-20 is an excellent candidate fo r this sampling since it provides great return loss and directivity. The sampled signal, which consists of a sample of the original input signal plus some distortion, is inverted and then combined with the output of the first delay line. This procedure subtracts (through destructive interference) the sample of the original input signal, leaving only the dist ortion or error component. The error component is then amplified and combined with the output of the second delay line using another dire ctional coupler. In many cases, a 10dB coupler is used to combine the two signals. The XC2100A-10 is a perfect choice for this injection because it has tight coupling, superior directivity, and excellent match.

Place Manufacturing. USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Model XC2100A-20 Rev D RFP-500500A6Z50 RFP-375375A6Z5050 RFP-250375A4Z5015 RFP-060120A15Z508 MODELPower (Watts)

50 Ohm ** (see table below)

** RECOMMENDED TERMINATIONS TERMINATIONS COUPLER HYBRID 3dB 10dB DIRECTIONAL COUPLER COUPLER DIRECTIONAL 20dB -- 30dB OUTPUT INPUT ERROR AMPLIFIER CANCELLATION CARRIER DELAY DELAY AMPLIFIER MAIN 100 Figure ap.n.2-1. Generic Feed Forward Circuit Schematic Both directional couplers in the Figure ap.n.2-1 have one port terminated with a 50 Ω resistor. In order to achieve optimum performance, the termination mu st be chosen carefully. It is important to remember that a good termination will not only produce a good match at the input of the coupler, but will also maximize the isolation between the input port and isolated port. Furthermore, since the termination can pot entially absorb high levels of power, its maximum power rating should be chosen accordingly. A list of recommended term inations is shown in Figure ap.n.2-1. For an ideal lossless directional coupler, the power at the coupled and direct ports can be written as: WattsdB )(Coupling input coupled PP = Eq. ap.n.2-1 WattsdB )(Coupling input inputdirect PPP −= Eq. ap.n.2-2 where Pinput is the input power in Watts, and Coupling(dB) is the coupling value in dB.

USA/Canada: Toll Free: Europe: (315) 432-8909 (800) 411-6596 +44 2392-232392 Available on Tape and Reel for Pick and Place Manufacturing. Model XC2100A-20 Rev D Packaging and Ordering Information Parts are available in both reel and tube. Packaging follows EIA 481-2. Parts are oriented in tape and reel as shown below. Minimum order quantities are 2000 per reel and 30 per tube. See Model Numbers below for further ordering information. Xinger Coupler Frequency (MHz) Size (Inches) Coupling Value Plating Finish XC 0450 = 410-480 0900 = 800-1000 1900 = 1700-2000 2100 = 2000-2300 2500 = 2300-2700 3500 = 3300-3700 A = 0.56 x 0.35 B = 1.0 x 0.50 E = 0.56 x 0.20 L = 0.65 x 0.48 M= 0.40 x 0.20 P = 0.25 x 0.20 03 = 3dB 05 = 5dB 10 = 10dB 20 = 20dB 30 = 30dB P = Tin Lead S = Immersion Tin XX XXXX X - XX X