Terahertz (THz) microstrip patch antenna arrays have been designed on liquid crystalline polymer substrate at 0.835-, 0.635-, and 0.1-THz frequencies in such a way that they could be fabricated with the simple laboratory-based printed circuit board etching process. The antenna array at 0.835- and 0.635-THz frequencies may be deployed for various applications in medicine including cancer detection through THz spectroscopy techniques and vital sign detection through Doppler radar and/or on-body techniques. A prototype antenna array at 0.1-THz frequency has been fabricated and tested to verify the proposed designing approach. The measured and the simulation results of the tested 0.1-THz array are in good agreement.

A novel antenna beam-steering technology is proposed for emerging millimeter-wave (mm-wave), broadband mobile technologies such as 5G and beyond. A high-gain (23 dBi) antenna with 30° beam steering is designed and tested at around the 38 GHz band. A Fabry–Perot type leaky-wave antenna (LWA) is employed as the main radiating structure, with a tunable high-impedance surface (HIS) used as the ground plane. The HIS phase tuning is accomplished by electro-mechanically varying the displacement between the HIS periodic metasurface layer and the ground plane using a flexure amplified piezoelectric actuator (PEA). The antenna exhibits very low loss (<1 dB) along with fast (in the order of ms.) and continuous beam steering. The measured and simulated results show close agreement and suggest that PEA-tuned, metasurface-based antennas offer a promising solution for use in future mm-wave communication systems.

The microwave frequency band typically used for wireless communications will soon become saturated and will no longer be able to fulfill the high bandwidth demands of modern communication networks. Terahertz (THz) communication has appeared as a highly attractive, future-generation wireless technology that offers higher spectral bandwidth and, therefore, higher data rates. However, the full exploitation of THz technologies is contingent upon the availability of energy-efficient sources and devices. In this letter, we present a fabrication and measurement of a microscale planar inverted cone antenna array made of gold. Using an ungrounded coplanar waveguide (CPW) feed, the microfabricated structure provides a bandwidth of 37.9% with the resonant frequency of 0.925 THz. Given the cost of microfabrication is reduced substantially with rapid technological advancements, the results of this letter suggest that high-speed THz communications can be realized for wide-scale applications.

In this paper, ultra-wide patch antenna arrays have been presented at 60 GHz band (57.24–65.88 GHz) with improved gain and beam-width capabilities for remote detection of respiration and heart beat rate of a person with Doppler radar principle. The antennas measured and simulation results showed close agreement. The breathing rate (BR) and heart rate (HR) of a 31-year-old man have been accurately detected from various distances ranging from 5 to 200 cm with both single-antenna and dual-antenna operations. In the case of single-antenna operation, the signal is transmitted and received with the same antenna, whereas in dual-antenna operation, two identical antennas are employed, one for signal transmission and the other for reception. It has been found that in case of the single-antenna operation, the accuracy of the remote vital sign monitoring (RVSM) is good for short distance; however, in the case of the dual-antenna operations, the RVSM can be accurately carried out at relatively much longer distance. On the other hand, it has also been seen that the visual results are more obvious with higher gain antennas when the radar beam is confined just on the subject’s body area.

A beam scanning Fabry-Perot leaky-wave antenna (LWA) is designed at 60 GHz-band for single tone continuous-wave Doppler radar (DR)-based remote vital sign monitoring (RVSM) in a dynamic environment. A brief analysis is presented on antenna requirements for the DR in a typical dynamic scenario where a continuous RVSM is desired of a patient during sleep. The antenna is designed based on the drawn requirements with sufficiently high gain (>18 dBi) and wide beam scanning (12°) over the operating frequency band (62-65 GHz) for accurate RVSM up to 3 m distance. The patient under continuous health monitoring has a flexibility to change his/her position within 1 m angular distance from the fixed sensor position. Detailed RVSM measurements have been carried out with the proposed antenna system at 2 m and 3 m distances from the subject to verify the designed antenna's suitability for dynamic RVSM application. It has been shown that both the breathing rate (BR) and heartbeat rate (HR) can be successfully detected within 20° of the angular range by tuning the operating frequency from 62 to 65 GHz.