A 0.85–1.25 GHz On‐Chip Tunable Bandpass Filter Using Cascaded Parametric Mixing in GaAs MMIC

ABSTRACT This paper presents the first fully integrated on‐chip realisation of a parametric frequency‐conversion bandpass filter implemented in GaAs MMIC technology, building upon a previously reported cascaded parametric mixer architecture. The filter employs cascaded parametric up‐ and down‐conversion stages centred around a fixed idler resonance, enabling frequency‐translated bandpass filtering with broadband tunability. With a fabricated size of 7.5 × 6.5 mm 2 , the filter operates over a tunable range of 0.85–1.25 GHz and achieves near‐unity gain in the passband with less than 3 dB insertion loss, greater than 30 dB out‐of‐band suppression and a measured noise figure of approximately 6 dB at unity gain. High linearity is demonstrated with a P1dB of −2 dBm, an in‐band IIP3 of 8.7 dBm and an out‐of‐band IIP3 of 28 dBm.