V-W Band CMOS Distributed Step Attenuator With low Phase Imbalance

• Published in: IEEE microwave and wireless components letters Vol. 24; no. 8; pp. 548 - 550
• Main Authors: Kim, Kyungwon, Lee, Hyo-Sung, Min, Byung-Wook
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2014; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Attenuation; Attenuation measurement; Attenuators; Circuit properties; CMOS; CMOS attenuator; CMOS integrated circuits; Compressing; Design. Technologies. Operation analysis. Testing; Electric, optical and optoelectronic circuits; Electronic devices; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Exact sciences and technology; Gain; Integrated circuits; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Noise levels; phase imbalance; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; step attenuator; Transistors; v-Band; variable attenuator; Varistors; w-band; step attenuator; Return loss; Shunt; Stacking; Microwave; variable attenuator; V band; Varistance; Millimetric wave; High power; w-band; CMOS attenuator; Complementary MOS technology; Insertion loss; Attenuator; W band; v-Band; MOS transistor; NMOS technology; Root mean square value; phase imbalance
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2014.2322442

This letter presents a high power V-W band CMOS distributed step attenuator with a low phase imbalance. Thirteen nMOS varistors are periodically placed in a t-line and change the attenuation in a step up to 10 dB. For high power handling, four-stacked and biased nMOS transistors are used for the varistor. Shunt t-lines under the varistors compensate for the phase imbalance of the attenuation states. The total chip size is 0.38 {\rm mm}^{2} excluding pads. The insertion loss of the attenuator is 5.6-11.2 dB at 50-110 GHz. The return loss is <- 15 dB at 50-110 GHz with the rms phase imbalance of <1.4^{\circ} and the input 1 dB compression point of 17 dBm.