Decade Tuning, Wide if Instrumentation Receiver

This paper describes the development of the receive section of an instrumentation transceiver. The radio is designed for high linearity, gain and phase flatness, and is capable of tuning from 0.4-4 GHz in 1 Hz steps with an IF bandwidth of 20 MHz. Its performance is intended to be capable of testing 2G, 3G, LTE, and WIMAX systems. A high first IF avoids multiple switched filters while maintaining good spurious performance. The design uses SMT packaged MMIC amplifiers and mixers, microstrip, coaxial resonator, and lumped element filter technologies and a high performance synthesiser architecture based around off-the-shelf VCOs. A 16 bit 130 MHz ADC takes the signal into the digital domain for final down conversion to complex base-band. Two high performance FPGAs are used for this processing and also implementation of digital equalisation and applying calibration offsets. A high speed serial link to further processing is available for further filtering and software defined demodulators.