Browsing by Author "Rieh, Jae-Sung"

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300-GHz Direct and Heterodyne Active Imagers Based on 0.13-mu m SiGe HBT Technology
(2017-09-01)
Yoon, Daekeun
;
Kim, Jungsoo
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Yun, Jongwon
;
Kaynak, Mehmet
;
Tillack, Bernd
300-GHz direct and heterodyne imagers based on a 0.13-mu m SiGe HBT technology were developed for active imaging applications in this work. The direct imager, which is based on the square-law principle, shows a maximum responsivity of 6121 V/W and a minimum noise equivalent power (NEP) of 21.2 pW/Hz(1/2) at 315 GHz. The heterodyne imager, which consists of a mixer, a local oscillator, an IF amplifier, and an IF detector, exhibits a maximum responsivity of 322 kV/W and a minimum NEP of 3.9 pW/Hz(1/2) at 300 GHz. Total dc power consumption of the direct imager is 0.6 mW, while the heterodyne imager consumes 21 mW. The chip areas of the direct and heterodyne imagers including the on-chip antenna are 460 x 410 and 610 x 610 mu m(2), respectively. To compare the performance of the two types of imagers for imaging applications, images from both imagers were acquired and compared with various output power levels of the signal source. It was demonstrated that the heterodyne imager shows much better image quality, especially when the signal source power is not sufficiently high.
A 270-GHz CMOS Triple-Push Ring Oscillator With a Coupled-Line Matching Network
(2019-09-01)
Kim, Sooyeon
;
Yoon, Daekeun
;
Rieh, Jae-Sung
;
國際半導體學院
;
International College of Semiconductor Technology
A design procedure is proposed for triple-push ring oscillators, and an oscillator employing a coupled line-matching network is developed following the procedure. This stepwise procedure, which uses power-dependent Z-parameters of transistors, is applied to the design of each amplifier stage constituting a ring oscillator based on its steady-state oscillation condition. It is verified with both L-section and T-section topologies assumed for the load of the amplifier stages of a given triple-push ring oscillator, and the differences between the two topologies are compared. Based on the procedure, a 270 GHz triple-push ring oscillator that employs coupled lines for matching networks has been developed in a 65-nm complementary metal-oxide-semiconductor (CMOS) process. The circuit benefits from the advantages of coupled lines such as compact area and simplified layout. The fabricated oscillator exhibits a measured oscillation frequency of around 270 GHz and output power of -10.9 dBm, with phase noise of -96 dBc/Hz at 10 MHz offset.
A 290-GHz CMOS Heterodyne Integrated Imager
(2016)
Yoon, Daekeun
;
Kim, Jungsoo
;
Rieh, Jae-Sung
;
國際半導體學院
;
International College of Semiconductor Technology
A 290-GHz heterodyne integrated imager has been developed in a 65-nm CMOS technology. The imager consists of a mixer, an LO (local oscillator), an IF amplifier, and an IF detector. A responsivity of 20 kV/W and a noise equivalent power (NEP) of 29 pW/Hz(1/2) were measured. Images were successfully acquired with an image acquisition setup that employs the fabricated imager circuit.
Approaches to Enhance the Performance of SiGe Imagers Operating near 130 GHz and 300 GHz
(2016)
Rieh, Jae-Sung
;
Yoon, Daekeun
;
Yun, Jongwon
;
Song, Kiryong
;
Kim, Jungsoo
A comparison is made on high-frequency SiGe imagers to investigate the performance enhancement with circuit-level approaches: employing a front-end low noise amplifier (LNA) and employing heterodyne topology. Two imagers operating near 130 GHz, one with and the other without an LNA, were compared for the responsivity and the noise equivalent power (NEP). Also, two imagers operating near 300 GHz, one in direct and the other in heterodyne topology, were compared for the same parameters. Inserting a front-end LNA has led to changes in the peak responsivity and the minimum NEP with a factor of 63.5 and 0.011, respectively, near 130 GHz. Employing heterodyne topology for the 300 GHz imager resulted in changes with a factor of 52.8 and 0.18 for the same parameters.
Terahertz InP HBT Oscillators
(2018-01-01)
Rieh, Jae-Sung
;
Yun, Jongwon
;
Yoon, Daekeun
;
Kim, Jungsoo
;
Son, Heekang
An overview of various high-frequency InP HBT oscillators that can be used as terahertz signal sources is presented. A 300-GHz fundamental-mode oscillator was first developed based on InP HBT technology, and then subsequently modified for additional oscillators with improved function or performance, which includes a 300-GHz voltage-controlled oscillator (VCO), a 280-GHz high-power oscillator with 10-dBm output, and a 600-GHz push-push oscillator. The 300-GHz oscillator was also successfully employed as a signal source for THz imaging, which is also briefly described.
Terahertz Reflection-Mode Biological Imaging Based on InP HBT Source and Detector
(2017-05-01)
Yun, Jongwon
;
Oh, Seung Jae
;
Song, Kiryong
;
Yoon, Daekeun
;
Son, Hye Young
This paper presents the development of an oscillator and a detector based on InP HBT technology operating near 300 GHz, and their application to terahertz reflection-mode imaging. The fabricated fundamental-mode common-base (CB) cross-coupled oscillator exhibits a peak output power of 5.3 dBm at 305.8 GHz, and the CB direct detector shows a responsivity higher than 40 kV/W and noise equivalent power lower than 35 pW/root Hz for a frequency range of 270-345 GHz. The imaging system employing the fabricated circuits as the signal source and detector was characterized for the resolution and dynamic range, and then, successfully applied for imaging various biological samples. The results show that low-power terahertz reflection-mode imaging based on solid-state electronic sources and detectors based on a commercial semiconductor technology is promising for various biomedical imaging applications.
Three-Dimensional Terahertz Tomography With Transistor-Based Signal Source and Detector Circuits Operating Near 300 GHz
(2018-09-01)
Kim, Jungsoo
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Yoon, Daekeun
;
Yun, Jongwon
;
Song, Kiryong
;
Kaynak, Mehmet
In this paper, three-dimensional (3-D) terahertz (THz) tomography was demonstrated with a signal source and imagers based on transistor circuits fabricated with standard semiconductor technologies. For the signal source, a 300-GHz oscillator based on InP HBT technology was employed. For detection, two types of imagers operating near 300 GHz were employed, one direct and the other heterodyne, both realized with SiGe HBT technology. With a set of 2-D images taken from different angles, sinograms and tomograms were obtained, which led to a successful reconstruction of 3-D images of the target object based on the filtered back-projection algorithm. A systematic comparison was made for the direct imager and the heterodyne imager, for which the signal input power and the video bandwidth were varied for both imagers. The results revealed that the heterodyne imager shows a better sensitivity than the direct imager. However, a similar dynamic range of around 30 dB was achieved for both imagers because of a saturation observed for the heterodyne imager when the input power exceeds the threshold. The video bandwidth did not affect the image quality significantly for the bandwidth variation over four orders of magnitude for both imagers.