A tunable ultra‐wideband superheterodyne radio frequency receiver with high‐image‐rejection levels

This article presents the superheterodyne radio frequency (RF) receiver composed of two receiving channels, which can realize an ultra-wide receiving frequency band. The RF signal can be received and demodulated in a variable frequency band by controlling the voltage of RF switches, which makes the RF signal enter the appropriate frequency conversion channel and tuning the local oscillator frequency according to the RF signal frequency. Therefore, the receiver realizes the adjustable working frequency band and an ultra-wide receiving frequency band. The designed superheterodyne RF receiver is simulated, manufactured, and measured. Finally, the article achieves a tunable ultra-wideband superheterodyne RF receiver with an image-rejection architecture that can provide rejection of more than 29.0 dB. The receiving frequency band of the receiver is 2.5 GHz –12 GHz. When the proposed receiver link receives multiple types of quadrature signals with a symbol rate of 50 M Baud, the error vector magnitude is less than 1.90%.