Suren Gigoyan

Silicon-on-Glass Dielectric Waveguide—Part I: For Millimeter-Wave Integrated Circuits

A low-cost Silicon-on-Glass (SOG) integrated circuit technology is proposed for millimeter-wave (mmW) applications, for the first time. In the proposed technology, all mmW passive components are made of high-resistivity Silicon (Si) on a glass substrate. The proposed technique leads to a high-precision and low-cost fabrication process, which eliminates the need for costly assembly of the complex structures. This is achieved by photolithography and dry etching of the entire integrated passive circuit through the Si layer of the SOG wafer. Silicon-on-Glass dielectric waveguide, as the basic component of the SOG integrated circuit, is theoretically and experimentally investigated. A test setup is designed to measure propagation characteristics of the proposed SOG waveguide. Measured dispersion diagrams of the SOG dielectric waveguide show average attenuation constants of 0.63 dB/cm, 0.28 dB/cm, and 0.53 dB/cm over 55-65 GHz, 90-110 GHz, and 140-170 GHz, respectively.

Whispering-gallery-mode resonance sensor for dielectric sensing of drug tablets

We propose, for the first time, the application of whispering gallery mode (WGM) perturbation technique in dielectric analysis of disk shape pharmaceutical tablets. Based on WGM resonance, a low-cost high sensitivity sensor in milllimeter-wave frequency range is presented. A comprehensive sensitivity analysis was performed to show that a change in the order of 10−4 in the sample permittivity can be detected by the proposed sensor. The results of various experiments carried out on drug tablets are reported to demonstrate the potential multifunctional capabilities of the sensor in moisture sensing, counterfeit drug detection and contamination screening. Analytically, two sample placement configurations, i.e. a tablet placed on top of a dielectric disk resonator and inside a dielectric ring resonator, have been studied to predict the resonance frequency and Q-factor of the combined sample-resonator structure. The accuracy of the analytical model was tested against full-wave simulations and experimental data.

Millimeter-Wave Silicon-on-Glass Integrated Tapered Antenna

This letter presents a millimeter-wave (mmW) high-efficiency tapered dielectric antenna, which is designed and fabricated on a new integrated technology platform called silicon-on-glass (SOG). The antenna is fabricated using photolithography and dry etching of the Si layer of the SOG wafer. The proposed antenna advantages include high efficiency, low-cost fabrication with high precision, and small size. Experimental results are presented to validate the new design concept, which is optimized for low sidelobe, high gain, and short length.

Millimeter-Wave Suspended Silicon-on-Glass Tapered Antenna With Dual-Mode Operation

A highly efficient millimeter-wave (mmW)/Terahertz (THz) dielectric antenna is proposed. The proposed suspended tapered antenna [made of high resistivity silicon (Si)] is fabricated in a new mmW/THz integrated technology platform called silicon-on-glass (SOG). The fabrication process makes the tapered antenna with deep reactive ion etching of the Si layer of the SOG platform, wherein a part of the glass substrate below the antenna tapered section is etched. The glass substrate below the antenna is etched in hydrofluoric acid (HF 49%) before bonding to the Si wafer. The antenna is designed to radiate both Ex-and Ey-polarizations over the frequency band of 110-130 GHz and features additional advantages including highly linear polarization, high-directivity, integrability, and low-cost fabrication. Numerical and experimental results are presented to validate the high-performance proposed antenna. Experiments show gains of 17.5 dBi at 115 GHz and 18.3 dBi at 128 GHz for Ex11 -and Ey11 , -modes excitations, respectively. These two polarizations show measured efficiencies of 94% and 99%, respectively.

Tapered dielectric image-line antenna array for millimeter-wave applications

In this paper, a high-gain tapered dielectric image-line (DIL) antenna array is presented for 30 GHz frequency range. Each element of the array is designed and optimized for maximum gain and minimum side-lobes. A novel array structure is proposed to increase the gain and suppress the side-lobs. An estimated 21.5 dB gain has been achieved with a 3-element array structure. The measurement results are presented and are compared with the simulation results.

Mode-selective dielectric resonator coupled to dielectric image waveguide for sensing applications

In this paper, multi-mode dielectric resonators coupled to dielectric image waveguides are investigated for mm-wave sensing applications. It is demonstrated both numerically and experimentally that for each resonance mode, there is a critical coupling condition under which the corresponding mode will have a pronounced response with higher Q-factor compared to the other existing resonance modes. The proposed structure is attractive for sensor devices with high sensitivity, particularly because its resonance frequency can be adjusted over a wide range of millimeter-wave spectrum.

Low Loss, Wideband, and Compact CPW-Based Phase Shifter for Millimeter-Wave Applications

This paper proposes a compact, low-loss, and low cost phase shifter for millimeter-wave phased array systems. The basic idea is to modify the propagation mode of a coplanar waveguide (CPW) by placing a high dielectric constant (40 <; εr <; 170) slab on top of it. The phase shift is varied by changing the air gap between the CPW line and the dielectric slab. A piezoelectric transducer has been used to control this air gap precisely. For fast but accurate modeling of the proposed phase shifter, two methods one based on spectral domain analysis and the other based on the conformal mapping have been developed and verified with full wave simulations and measurements. A prototype structure with the operational frequency range from 20 to 40 GHz is presented. The maximum phase shift obtained for the electrically controlled version at 40 GHz is 103 ° with loss variation of 0.2 dB. The total length is 2 mm.

Low insertion loss variable phase shifter for emerging millimeter-wave communication systems

This paper proposes a compact, low-loss, and low cost phase shifter for mmWave applications. The basic idea is perturbing the propagation constant of a CPW line by its loading with a high dielectric constant BLT ceramic. The phase shift is sensitive to the air gap between the CPW and the BLT sample. For a sample with a length of 3mm, a phase shift of 170° at 30GHz is obtained while the average insertion loss is less than 1.45dB with a variation of 1.1dB for the full range of phase shifts.

A low-cost silicon-based beam-steering grating antenna for G-band applications

This paper presents a Dielectric Image Guide (DIG) beam-steering antenna for operating at G-band. The antenna, which is made of High Resistive Silicon (HRS), is essentially a leaky wave antenna with uniform grating on top. A very accurate, fast, and low-cost laser fabrication process is developed and used for the proposed structure. The radiation mechanism is investigated using full-wave electromagnetic simulations. The antenna provides a frequency-scanning capability up to 20° over the frequency range between 153-165 GHz. The optimized antenna achieves radiation efficiency better than 94% and max gain of 14.2 dBi, which drops only 0.5 dB all over the beam scanning range. The antenna return loss is better than 10 dB over the scanning range.

Label-free DNA sensing using millimeter-wave silicon WGM resonator

A planar dielectric waveguide based structure for bio-sensing purpose is introduced. The proposed device is a silicon-based WGM disc resonator operating within the range of 75-110 GHz (W-band). The sensor is an integrated, miniaturized, low-cost, and easy-to-fabricate bio-sensor structure. The proposed sensor can be used for a number of DNA characterization tasks including Mutation in DNA oligonucleotide. Two types of DNAs, single strand and double strand DNAs, are successfully tested by our integrated sensor. The measurement repeatability and selectivity of the proposed sensor are examined through the different experimental lab-tests.