Design of a Q-Band 0.18-µm CMOS band-pass attenuator

Attenuators and band-pass filters (BPFs) are widely employed in communication and radar systems as amplitude controllable and frequency selective circuits, respectively. To achieve both band-pass filtering and attenuating responses in systems, BPF and wideband attenuator are typically cascaded together as depicted in Fig. 1(a). This conventional approach, integrating two individual components, leads to an overall large circuit size and high insertion loss. To alleviate this problem, a dual-function attenuator incorporating an embedded band-pass filtering function as part of the attenuation circuitry could be employed as described in Fig. 1(b).