Abstract-High-Tc Superconducting Fourth-Harmonic Mixer Using a Dual-Band Terahertz On-Chip Antenna of High Coupling Efficiency

Xiang Gao, Jia Du, Ting Zhang,  Y. Jay Guo

https://ieeexplore.ieee.org/document/8534418

This paper presents a dual-band on-chip antenna-coupled high-Tc superconducting (HTS) Josephson-junction subterahertz (THz) fourth-harmonic mixer. The antenna utilizes a couple of different structured twin slots to enable the resonant radiations at two frequencies, and integrates a well-designed coplanar waveguide network for achieving good radiation coupling and signal isolation characteristics. The electromagnetic simulations show that coupling efficiencies as high as -4 and -3.5 dB are achieved for the 160- and 640-GHz operating frequency bands, respectively. Based on this dual-band antenna, a 640-GHz HTS fourth-harmonic mixer is developed and characterized in a range of operating temperatures. The mixer exhibits a measured conversion gain of around -18 dB at 20 K and -22 dB at 40 K, respectively. The achieved intermediate frequency bandwidth is larger than 23 GHz. These are the best results reported for HTS harmonic mixers at comparable sub-THz frequency bands to date.

Abstract -On Chip Antenna Measurement: A Survey of Challenges and Recent Trends

M. Rashid Karim,  Xiaodong Yang, Muhammad Farhan Shafique

https://ieeexplore.ieee.org/document/8328817/

Exponential increase in the requirements of cost effective and highly compact wireless modules has put system-on-chip (SoC) technology in high demand. On-chip-antenna (OCA) is an integral component of SoC-based wireless communication systems and has emerged as a perfect candidate for plethora of promising applications, especially at millimeter wave and terahertz frequencies. OCAs also support compact and low power applications of wireless sensor networks and Internet-of-Things. Since OCAs are manufactured on a single substrate along with other components, therefore their successful realization is subject to several challenges; the most significant of which is their accurate measurement. OCA's precise characterization is considered to be one of the toughest challenges to overcome since traditional off-chip antenna measurement setups are not suitable for this job. This calls for innovative measurement techniques, setups and solutions to enable their true characterization. Inspired by the significance of OCA characterization, this paper presents a comprehensive survey of the key recent developments in the field of OCA measurements. The techniques used to measure conventional off-chip antennas are briefly outlined followed by a succinct description of OCA's characterization challenges. The most recent trends and techniques of OCA measurement are expansively compiled. Some avenues for future trends in this regards are also delineated. It is anticipated that the presentation of this review will inspire the research community to come up with the novel methods and proposals to facilitate the OCA characterization process.https://ieeexplore.ieee.org/document/8328817/

Abstract-CMOS terahertz imaging pixel with a small on-chip antenna

Shota Hiramatsu, Kosuke Wakita, Seokjin Na, Sayuri Yokoyama, Masayuki Ikebe, Eiichi Sano

https://www.semanticscholar.org/paper/CMOS-terahertz-imaging-pixel-with-a-small-on-chip-Hiramatsu-Wakita/17df7830e3e10988ebd69b16718b1c76c6160eee

We propose a Si–CMOS terahertz image sensor to resolve the lack of low-cost and small-size detectors. The imager chip consists of an imaging pixel array and column ADCs. The imaging pixel consists of an on-chip antenna and an amplifier acting as envelope detector. The pixel used a microstrip patch antenna for receiving THz waves. However, these antennas’ narrow bandwidth and large ground-plane size cause major problems. A low-resistivity Si substrate degrades the gains of planar antennas apart from the microstrip patch antenna. We introduce an on-chip folded-slot antenna to reduce the pixel size and prevent gain degradation due to the Si substrate. The antenna has a broader bandwidth and higher gain than conventional on-chip slot antenna. The folded-slot antenna has about a 0-dBi gain at 0.85 THz and a broader bandwidth than the microstrip antenna in the 0.85 to 1 THz frequency region. The measured results for the THz image sensors with the integrated folded-slot antennas will be reported in near future.