Design of a broadband bidirectional converter

Frequency converters play a key role in wireless communication systems, which give conversion between the radio frequency (RF) band and the intermediate frequency (IF) band. This paper presents the design of a 2–18 GHz broadband bidirectional converter, in which up-conversion and down-conversion channels work in time division multiplexing (TDM). For down-conversion, the noise figure of the down-converter is less than 7 dB, the input dynamic range is more than 70 dB and the spurious signal level is less than -55 dBm, respectively. For up conversion, it supports more than 10 dBm output power and over 30 dB digital attenuation range. The spurious signal level is also less than -55 dBm. Furthermore, the size of the RF circuit is greatly miniaturized by employing the integrated GaAs filter bank.