This paper presents a Ka-band 4-bit BiCMOS digital step attenuator with maximum attenuation of 7.5 dB (16 states). The proposed attenuator design is based on switched T-bridge network including phase correction network and is fabricated in 0.13 μm SiGe BiCMOS technology. Attenuator with phase correction structure shows root mean square (RMS) amplitude errors <0.8 dB at 31 to 33 GHz and the RMS insertion phase varying from 2.8° to 5.8° over 31-33 GHz. The measured insertion loss is 19 dB and total chip size including pad is 1.92×0.4 mm2.
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