As shown in FIG. 9C, RF signals output by receive antenna 122 may be provided, via line 933, to amplifier 940, which may amplify the signals and provide the amplified signals to filter 942. Filter 942 may be a high-pass or any other suitable type of filter and may filter signals received from amplifier 940 and provide the filtered signals to amplifiers 944 and 946. Signals amplified by amplifiers 944 and 946 may be filtered by filter 948 and subsequently provided to one of the inputs of frequency mixer 945. The other input of frequency mixer 945 receives signals generated by the signal chain that begins with signals generated by local oscillator 932. The signals output by local oscillator 932 may be provided to frequency multiplier 934 and subsequently to amplifier 936. Signals amplified by amplifier 936 are provided to frequency mixer 945.
