Texas Instruments TRF1500 manual Low-Band Mixer LO Input, Low-Band if Output

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SWRA004A

Low-Band Mixer LO Input

Figure 8 details the low-band mixer LO input configuration. The input power range level for the LO buffer amplifier is flexible enough (-3 dBm to -7 dBm) to drive the mixer without entering compression. The LO signal is injected through an internal LO buffer amplifier and into the mixer. A high pass shunt-L (L14) and series-C (C17) network is used for impedance matching. The inductor also shunts to ground any undesired noise that could be injected to the mixer.

Figure 8. Low-Band Mixer LO Input Configuration

Low-Band IF Output

Figure 9 details the low-band IF output configuration. The low- band mixer has a differential IF output with a 1kΩ differential output impedance. For evaluation, a 16:1 transformer balun, with a insertion loss of 1.8 dB, is used to transform the 1kΩ differential output to a single-ended output which is then matched to 50Ω. In the actual application, the IF output is usually connected to a narrow band channel select filter with a differential input and the transformer balun is not required.

The supply voltage (VCC) is applied to the IF pins with pull up inductors (L12, L13). A low-pass filter network is provided prior to the balun. The filter also acts as part of the impedance matching network. During optimization of the output matching network, it was found that mismatching the differential output, accomplished with C55, gives the best IIP3 performance with minimum effect on the gain and noise figure performance. C55 also helps to decouple the digital CMOS control line from the LO signal. The IF response is shaped by the shunt-L (L51) after the transformer balun. L51 is also used to block unwanted noise that could be reflected back to the mixer. The series capacitor (C51) near the LB_IF_OUT port is used as a dc block for evaluation purposes and does not have to be implemented in the end-users system.

TRF1500 Integrated Dual-Band RF Receiver User’s Guide

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Contents TRF1500 Integrated Dual-Band RF Receiver User’s Guide Important Notice Trademarks PIC Telephone Contents Appendix a Test Bench Configuration Figures TablesTRF1500 Integrated Dual-Band RF Receiver User’s Guide AbstractProduct Support Ingl E Chip Anal OG AS E BRelated Documentation World Wide WebIntroduction External Components Design ConsiderationsBoard Design and Impedance Matching TRF1500 Dual-Band Receiver Block Diagram TRF 1500 Dual-Band ReceiverPin Descriptions Pin Number Name DescriptionStrong Signal TRF1500 Control State Control State and the Corresponding Active CircuitsCascaded Block Diagram of the Low-Band Receiver Section Low-Band LNA Low-Band LNA Turn on TimeLow-Band LNA Input Low-Band LNA OutputLow-Band LNA Output Configuration Surface Acoustic Wave SAW FilterLow-Band Mixer Low-Band Mixer RF InputLow-Band Mixer LO Input Low-Band if OutputLow-Band if Output Configuration Low-Band LO Buffer Amplifier OutputLow-Band Buffer Amplifier Output Configuration Low-Band Cascaded Test Guide LOW-Band Cascaded Power Conversion GainLB LNA, LB Mixer, SAW Filter, and LB if Amp Parameters Low-Band Cascaded Power Conversion Gain Reduction Low-Band Cascaded Noise Figure TRF1500 Integrated Dual-Band RF Receiver User’s Guide Low-Band Cascaded RF Input Return Loss Low-Band Cascaded LO Input Return LossLOW Band LO Buffer Output Power Low-Band Power Leakage LO In to RFLow-Band Cascaded Third Order Input Intercept Point IIP3 Low-Band Cascaded 1dB RF Input Compression Point Low-Band Cascaded 1dB Blocking Point Block Diagram of the High-Band Receiver Section High-Band RF Input High-Band LO InputHigh-Band LO Frequency Doubler Driven Configuration High-Band if Output Configuration High-Band if OutputHigh-Band LO Buffer Amplifier Output Configuration High-Band LO Buffer Amplifier OutputHigh-Band Cascaded Test Guide High-Band Cascaded Power Conversion GainHB LNA, HB mixer, HB if amp High-Band Cascaded Power Conversion Gain Reduction High-Band Cascaded Image Rejection High-Band Cascaded Noise Figure High-Band Cascaded RF Input Return Loss High-Band LO Buffer Output Power High-Band Cascaded Power Leakage LO In to RF High-Band Cascaded Third Order Input Intercept Point IIP3High-Band Cascaded 1dB Input Compression Point High-Band Cascaded 2X2 Spur Performance High Band 3X3 Spur Performance Low- and High-Band Transmit Mixer Low-Band and High-Band TransmitLow-Band and High-Band Transmit Mixer RF Input Low- and High-Band Transmit Mixer RF Input Configuration Low- and High-Band Transmit Mixer if Output ConfigurationLow-Band Transmit Mixer Test Guide Low-Band Transmit Mixer Power Conversion GainLow-Band Transmit Performance Parameters Low-Band Transmit Mixer Noise Figure Low-Band Transmit Mixer Input Return Loss Low-Band Transmit Mixer Power Leakage LO In to TX Low-Band Transmit Mixer Power Leakage TX In to LOLow-Band Transmit Mixer 1dB Input Compression Point See Appendix a Test Bench Setups See Appendix a Test Bench Setups High-Band Transmit Mixer Test Guide High-Band Transmit Mixer Performance ParametersLow-Band LNA Input Return Loss Low-Band LNA Stand-Alone Test GuideLow-Band LNA Gain Low-Band LNA ParametersLow-Band LNA Isolation Low-Band LNA Output Return LossLow-Band LNA 1dB Input Compression Point Low-Band LNA Noise Figure Low-Band LNA Third Order Input Intercept Point IIP3 TRF1500 Integrated Dual-Band RF Receiver User’s Guide Low-Band Receiver Mixer Stand-Alone Test Guide Low-Band Receiver Mixer Power Conversion GainLow-Band Receiver Mixer Parameters Low-Band Receiver Mixer Input Return Loss Low-Band Receiver Mixer Power Leakage LO In to RF Low-Band Receiver Mixer Noise FigureTRF1500 Integrated Dual-Band RF Receiver User’s Guide Low-Band Receiver Mixer 1dB RF Input Compression Point 12.2 11.4 10.4 ←1dB Compression Point TRF1500 Integrated Dual-Band RF Receiver User’s Guide Appendix a Test Bench Configuration Test Bench Setup Noise Figure Test Bench Setup Power Leakage RF In to LO In Measurements Test Bench Setup LNA 1dB Input Compression Point