180 to 240 GHz broadband, EM‐based power amplifier using 0.5‐μm InP DHBT technology

Abstract

This paper reports a power amplifier (PA) terahertz monolithic integrated circuit (TMIC) from 180 to 240 GHz. This amplifier is fabricated from a 0.5-μm indium phosphide double heterojunction bipolar transistor (InP DHBT) technology, jointly with a thin-film microstrip wiring environment. Furthermore, an electromagnetic (EM) simulation method is proposed for the parameter extraction of InP DHBTs and amplifier design. This five-stage amplifier has >6.1 dB S 21 gain from 180 to 240 GHz, peaks 10.4 dB S 21 gain at 210 GHz. At 213 GHz operation, the saturated output power is 5.8 dBm with 7.3 dB large-signal gain, and this amplifier occupies 2.52 mm 2 including pads. KEYWORDSEM-based simulation method, InP DHBT, power amplifier, TMIC | INTRODUCTIONReflecting the development at terahertz frequencies, many unique applications have appeared including the imaging radar at 220 GHz, 1 the high-data-rate communications at 240 GHz, 2 and many other newly minted application. 3 However, the lack of broadband and high-power terahertz sources is a serious obstacle to THz technology. To address this problem, many researchers put a lot of effort into the research of semiconductor devices. As a result, InP HEMTs and InP HBTs have been demonstrated with maximum frequencies of oscillation ( f max ) exceeding 1 THz. 4-6 Besides, benefited from high electron mobility and breakdown voltage, InP DHBTs have been a preferred technology in the monolithic integrated circuits operating at terahertz frequencies. 5 A more accurate transistor model will be necessary to predict the performance of the TMIC with the increase of frequency. However, the accuracy and reliability of the model is affected by sensitive components to parasitic effects at terahertz frequency. The emergence of the 3D electromagnetic simulation method makes it possible to characterize various effects operating at terahertz frequencies, and this method has been implemented on on-wafer parasitic parameter de-embedding and peripheral passive element extraction. [7][8][9] In this paper, based on our previous work, 10-14 an electromagnetic (EM) simulation method is proposed for the parameter extraction of DHBTs, and a 220 GHz PA TMIC using 0.5-μm InP HBT technology is designed. This amplifier offers over 6.1 dB small-signal gain from 180 to 240 GHz, while 5.8 dBm saturated output power at 213 GHz.

Guest Editorial for the special issue on devices and circuits for millimeter‐wave and THz applications

“…In the design of InP HBT‐based circuits, Cui et al reported a broadband subharmonic mixer in the frequency range of 199 to 238 GHz by combining the diode SPICE model and 3D full‐wave electromagnetic (EM) model. Li et al proposed an EM simulation‐based method for InP HBTs model parameter extraction, which is applied to 180 to 240 GHz amplifier design. Passive device models in CMOS technology are quite complicated due to the small area.…”