QUICK START GUIDE FOR DEMONSTRATION CIRCUIT DC963B LOW POWER ACTIVE UP-CONVERTING MIXER LT5560 DESCRIPTION Demonstration circuit DC963B is optimized for an up- down-conversion mixer in a wide variety of converting mixer test & measurement for input applications. frequency range of 45MHz to 190MHz, output frequency range of 850MHz to 935MHz, (12dB return The LT 5560 is characterized with a supply current of loss BW). The LO port frequency range is 520MHz to 10mA however, the DC current is adjustable, which 920MHz (10dB return loss BW). allows the performance to be optimized for each The LT 5560 is a 0.01MHz to 4000MHz low power, application by changing the value of resistor R1. For high performance broadband Up/Down-converting Icc=10mA the value of R1 = 3 Ohm. Operation at a active mixer. This double-balanced mixer can be lower supply current will, however, degrade linearity. driven by a single-ended LO source and requires minus 2dBm of LO power. The signal ports can be Design files for this circuit board are available. Call impedance matched to a broad range of frequencies, the LTC factory. which allow the LT 5560 to be used as an up- or LT is a registered trademark of Linear Technology Corporation. Table 1. Typical Performance Summary (T = 25C) A PARAMETER CONDITION (f = 140MHz, f =760MHz) VALUE INPUT LO Supply Voltage 2.7V to 5.0V Supply Current V = 3V, EN = High, R1=3 10mA CC Maximum Shutdown Current V = 3V, EN = 0.3V 10A CC Signal Input Frequency Range Requires External Matching < 4000MHz LO Signal Frequency Range Requires External Matching < 4000MHz Signal Output Frequency Range Requires External Matching < 4000MHz IF Input Return Loss Z = 50, with External Matching 15dB 0 LO Input Return Loss Z = 50, with External Matching 15dB 0 RF Output Return Loss Z = 50, with External Matching 15dB 0 LO Input Power -6dBm to 1dBm Conversion Gain P = -20dBm, P = -2dBm 2.4dB INPUT LO SSB Noise Figure P = -2dBm 9.3dB LO rd Input 3 Order Intercept 2-Tone, -20dBm/Tone, f = 1MHz, P = -2dBm +9.0dBm LO nd Input 2 Order Intercept 2-Tone, -20dBm/Tone, f = 1MHz, P = -2dBm +47dBm LO Input 1dB Compression P = -2dBm -2.8dBm LO LO to IN leakage P = -2dBm -54dBm LO LO to OUT leakage P = -2dBm -41dBm LO 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT DC963B LOW POWER ACTIVE UP-CONVERTING MIXER QUICK START PROCEDURE Demonstration circuit DC963B is easy to set up to input port, one at 140MHz, and the other at evaluate the performance of the LT 5560. Refer to 141MHz. Figure 1 for proper measurement equipment setup rd 6. To measure 3 order distortion and conversion and follow the procedure below: gain, set the Spectrum Analyzer start and stop NOTE: frequencies to 898MHz and 903MHz, respectively. Sufficient spectrum analyzer input attenuation a. Use high performance signal generators with nd rd should be used to avoid distortion in the low harmonic output for 2 & 3 order instrument. distortion measurements. Otherwise, low-pass rd filters at the signal generator outputs should be 7. The 3 order intercept point is equal to (P P ) / 1 3 nd used to suppress harmonics, particularly the 2 2 + P , where P is the power level of the two in 1 harmonic. fundamental output tones at 900MHz and rd 901MHz, P is the 3 order product at 899MHz 3 b. High quality combiners that provide a 50 Ohm and 902MHz, and P is the input power (in this in termination on all ports and have good port-to- case, -20dBm). All units are in dBm. port isolation should be used. Attenuators on nd the outputs of the signal generators are 8. Output 2 order distortion product (OIM2) can be recommended to further improve source measured at 1041MHz, (140MHz+141MHz) + nd isolation and to reduce reflection into the 760MHz = 1041MHz. To measure 2 order sources. distortion, set the Spectrum Analyzer start and stop frequencies to 1040MHz and 1042MHz, 1. Connect all test equipment as shown in Figure 1. respectively. Sufficient spectrum analyzer input 2. Set the DC power supplys current limit to 15mA, attenuation should be used to avoid distortion in and adjust output voltage to 3V. the instrument. nd 3. Connect Vcc to the 3V DC supply, and then 9. The input referred 2 order intercept point (IIP2) connect EN to 3V the Mixer is enabled (on). is equal to P P + P , where P is the power 1 2 in 1 level of the fundamental output tone at 900MHz or 4. Set Signal Generator 1 to provide a 760MHz, nd 901MHz, P is the 2 order distortion product at 2 -2dBm, CW signal to the demo board LO input 1041MHz, and P is the input power (in this case - in port. 20dBm). 5. Set the Signal Generators 2 and 3 to provide two -20dBm CW signals to the demo board RF 2