Daekeun Yoon

300 GHz Integrated Heterodyne Receiver and Transmitter With On-Chip Fundamental Local Oscillator and Mixers

A 300 GHz integrated heterodyne receiver and transmitter for wideband communication and imaging applications have been developed in a 250 nm InP double-heterojunction bipolar transistor (DHBT) process. The receiver integrates a 300 GHz RF amplifier with a balun, a down-conversion mixer with an IF amplifier, and a local oscillator, all on a single chip. The transmitter is composed of the identical circuit blocks of RF amplifier and oscillator in addition to an up-conversion mixer. Compared to previous integrated receivers and transmitters reported at above 200 GHz, the proposed work includes the on-chip local oscillator and mixers operating at a fundamental mode. This simplifies the system architecture, thus not only reducing the chip area and DC consumption but also improving the RF performance such as high conversion gain, low spurious levels, and low noise figure. The receiver exhibits a peak conversion gain of 26 dB at 298 GHz, 3-dB bandwidth of 20 GHz, and noise figure of 12.0-16.3 dB at IF frequency from 1.1 to 7.7 GHz. The transmitter exhibits peak conversion gain of 25 dB, 3 dB bandwidth of 18 GHz, and output power of -2.3 dBm. The DC power consumption of the receiver and transmitter are 482 and 452 mW, respectively.

300-GHz InP HBT Oscillators Based on Common-Base Cross-Coupled Topology

Two fundamental-mode oscillators operating around 300 GHz, a fixed-frequency oscillator and a voltage-controlled oscillator (VCO), have been developed in this work based on a 250-nm InP heterojunction bipolar transistor (HBT) technology. Both oscillators adopted the common-base configuration for the cross-coupled oscillator core, providing higher oscillation frequency compared to the conventional common-emitter cross-coupled topology. The fabricated fixed-frequency oscillator and the VCO exhibited oscillation frequency of 305.8 GHz and 298.1-316.1 GHz (18-GHz tuning range) at dc power dissipation of 87.4 and 88.1 mW, respectively. The phase noise of the fixed-frequency oscillator was measured to be -116.5 dBc/Hz at 10 MHz offset. The peak output power of 5.3 dBm (3.8% dc-to-RF efficiency) and 4.7 dBm (3.2% dc-to-RF efficiency) were respectively achieved for the two oscillators, which are the highest reported power for a transistor-based single oscillator beyond 200 GHz.

A Wideband H-Band Image Detector Based on SiGe HBT Technology

A wideband H-band detector operating near 300 GHz has been developed based on SiGe HBT technology. The detector consists of an on-chip antenna and a HBT differential pair for square-law detection. It showed responsivity of more than 1,700 V/W and noise equivalent power (NEP) smaller than 180 pW/Hz 0.5 for the measured frequency range of 250–350 GHz. The maximum responsivity and the minimum NEP were 5,155 V/W and 57 pW/Hz 0.5 , respectively; both were obtained at 330 GHz with DC power dissipation at 9.1 W.

A 248–262 GHz InP HBT VCO with Interesting Tuning Behavior

A fundamental-mode common-base voltage-controlled oscillator (VCO) based on 250-nm InP heterojunction bipolar transistor (HBT) technology is reported. The VCO, which employs varactors implemented by connecting the base and emitter of npn transistors as tuning components, shows a tuning range of 247.8-262.2 GHz. The output power is greater than 0 dBm over the entire tuning range, and dissipated dc power is around 85 mW. An unexpected tuning behavior was observed, which was shown to arise from the internal parasitic base inductance of the transistors used for varactors in this work.

Two 320 GHz Signal Sources Based on SiGe HBT Technology

Two 320 GHz signal sources, a push-push oscillator and an integrated oscillator-doubler, based on a 130 nm SiGe HBT technology are reported. Both signal sources adopt a common-base cross-coupled topology as an oscillator core. The doubler employs a Gm-boosting technique for improved conversion loss. The push-push oscillator exhibits an output power of -6.3 dBm and a phase noise of -96.6 dBc/Hz at 10 MHz offset. The output power and the phase noise of the integrated oscillator-doubler are 1.6 dBm and -94.7 dBc/Hz at 10 MHz offset, respectively. They dissipate dc power of 101.2 mW and 197.4 mW, leading to DC-to-RF efficiency of 0.2 % and 0.7 %, respectively.

D-Band Heterodyne Integrated Imager in a 65-nm CMOS Technology

A D-band heterodyne integrated imager, consisting of a mixer, an oscillator, an IF amplifier, and an IF detector, has been developed in a 65-nm CMOS technology. A measured responsivity of 720 kV/W and noise equivalent power (NEP) of 0.9 pW/Hz1/2 were obtained at 125 GHz. A total dc power of 74 mW was dissipated. The chip size is 1200×800 μm2 including contact pads and an input balun. A D-band image was acquired with the imager serving as a detector. A significant resolution enhancement was demonstrated with a near-field imaging achieved by a metal plate with a pinhole in the imaging setup.

A 310–340-GHz Coupled-Line Voltage-Controlled Oscillator Based on 0.25-

A THz voltage-controlled oscillator (VCO) has been developed in this work based on a 0.25- μm InP heterojunction bipolar transistor (HBT) technology. The cross-coupled push-push oscillator adopted a novel coupled-line topology, in which the DC blocking capacitors and the load inductance are replaced by a pair of coupled-lines to improve the oscillation frequency and reduce the circuit area. Also, a base bias tuning was employed for effective oscillation frequency tuning. The circuit exhibited the voltage tuning from 309.5 GHz to 339.5 GHz, leading to a tuning range of 30 GHz. The maximum output power was -6.5 dBm at 334 GHz, achieved with a dc power consumption of 13.5 mW. Measured phase noise was -86.55 at 10-MHz offset. The circuit occupies only 0.014 mm 2 excluding the probing pads.

\mu

A 200 GHz heterodyne image receiver consisting of a mixer integrated with an on-chip voltage controlled oscillator (VCO) has been developed in a 0.18 μm SiGe BiCMOS technology. Incoming signals near 200 GHz are down-converted by the 3rd-order subharmonic mixer with V-band local oscillator (LO) pumping, which is provided by the Colpitts VCO with a stacked common-base buffer. The measured minimum conversion loss is 11.5 dB at 196 GHz with an input 1 db compression point (P -1 dB) of -13 dBm. The fabricated chip with an area of 600 × 400 μm2 including pads consumes total DC power of 25.5 mW. A two-dimensional 200 GHz image acquired with the receiver is presented to demonstrate its imaging application.

m InP HBT Technology

Challenges in the implementation of THz circuits based on Si-based technologies such as Si CMOS and SiGe HBT technologies are overviewed in this paper. Major challenges described in this work include the operation speed of Si devices, loss of Si substrate, model accuracy, uncertainty in EM simulation, and the presence of dummy patterns. Possible techniques to partly circumvent the challenges are also discussed. A review of recently reported Si-based circuits operating beyond 100 GHz is provided.

A 200 GHz Heterodyne Image Receiver With an Integrated VCO in a SiGe BiCMOS Technology

This paper reports a couple of key circuit blocks developed for heterodyne receiver front-ends operating near 140 ㎓ based on SiGe HBT technology. Firstly, a 123-㎓ oscillator was developed based on Colpitts topology, which showed - 5 ㏈m output power and phase noise of -107.34 ㏈c/㎐ at 10 ㎒. DC power dissipation was 25.6 ㎽. Secondly, a 135 ㎓ mixer was developed based on a modified Gilbert Cell topology, which exhibited a peak conversion gain of 3.6 ㏈ at 1 ㎓ IF at fixed LO frequency of 134 ㎓. DC power dissipation was 3 ㎽, which mostly comes from the buffer.