Here, for the first time, we propose a simple strategy to realize an ultra-wideband metamaterial absorber by using room temperature ionic liquids (ILs) which are new class of organic salts containing purely anions and cations. At first, microwave loss characteristics methylimidazolium ILs were investigated. The results reveal that these have large conductivities dielectric factors means high conductive microwaves can both be caused, IL with shorter carbon chain on cation has potential...

Here, the microwave-absorbing properties of 1-ethyl-3-methylimidazolium and 1-butyl-3-methylimidazolium ([E BMIm]+-based) room-temperature ionic liquids (ILs) with different anions were systematically investigated by measuring dielectric in 1–14 GHz microwave-frequency range. First, [E BMIm]+-based ILs studied a typical open-ended coaxial probe system. The results showed that real part permittivity values decreased from 13 to 4 loss tangent 5.91 0.24, meaning displayed high dielectric-loss...

The design, analysis, implementation and measurement of an integrated V-band receiver front-end based on 0.15 μm GaAs pHEMT process are presented in this paper. chip uses the super-heterodyne topology which consists a low noise amplifier, image reject mixer, multiply-by-four (×4) LO chain. In order to minimize power consumed by chain, active single-ended mixer is designed requires extremely -5 dBm. Meanwhile, effect signal coupling analyzed solutions proposed. By introducing appropriate...

Recently, all-metal nanostructures for perfect absorption of light have attracted much attention due to their excellent plasmonic and photonic properties, but only narrow bands were obtained in previous studies. In this paper, a new kind metallic metasurface with wideband visible is designed, which consists gold nanotriangle array on the opaque metal substrate. By combining different resonant modes gradual-changed triangular nanostructure, wide waveband region from 378 626 nm achieved more...

This paper presents a design methodology for wideband low noise amplifier (LNA) with flat gain and figure (NF). A parallel RC network loaded stub circuit is proposed to enhance simultaneous impedance matching. Moreover, the same structure applied compensate transistor roll-off frequency. By properly selecting lengths different stages, NF are obtained in wideband. The method verified by designing V-band 4-stage LNA based on 0.15 μm GaAs pHEMT process. features 15.2 dB average within 45–61 GHz...

This paper presents a Ka band eight-channel integrated packaged phased array receiver front-end for passive millimeter-wave imaging system. Since multiple receiving channels are in given package, the mutual coupling issue affecting channel will deteriorate quality. Therefore, this study, influence of on system pattern and amplitude phase error is analyzed, design requirements proposed according to results. During implementation, paths discussed, circuits path modeled designed reduce level...

Six-port technology has been widely used in microwave systems, such as interferometric passive imaging. In this paper, an integrated Ka-band (32-36 GHz) six-port chip based on the 0.15-μm GaAs is designed and fabricated to simplify circuit structure miniaturize volume of imaging system. The integrates two amplifiers, phase shifters, a part analog complex correlator. chip, crosstalk between amplifiers cannot be ignored. This paper analyzes influence isolation correlation results guide design....

In this paper, the design, fabrication, and measurement of a compact broadband (4–8 GHz) analog complex correlator for passive millimeter-wave imaging system are presented. To achieve high sensitivity integration system, wideband miniaturization required. The achieves wide bandwidth by using add-and-square method, which is composed six-port circuit detection circuit. order to realize correlator, realized on chip base 0.15-μm gallium arsenide (GaAs) process. influence mismatch that employs...

This paper presents the coupling effects analysis and suppression of a highly integrated receiver front-end MMIC for passive millimeter-wave imager system. The consists low-noise amplifier, double-balanced image-reject mixer, frequency quadrupler, analog phase shifter. In order to integrate these devices into compact single chip without affecting core performance, problems need be solved. We analyze influence on image rejection ratio, propose corresponding solutions three different paths....

This paper presents the design of a Ka-band phased-array radiometer front-end for passive millimeter-wave imaging systems, and proposes series measurement methods suitable such highly integrated multi-channel module. The integrates self-developed multifunctional active MMICs, multi-layer PCB circuits mechanical horn antennas through multichip module technology. Since multiple channels components are inside cannot be separated, some specific indicators has become difficult. In this study, by...

Human body temperature is a fundamental physiological sign that reflects the state of physical health. It important to achieve high-accuracy detection for non-contact human measurement. In this article, Ka band (32 36 GHz) analog complex correlator using integrated six-port chip proposed, and millimeter-wave thermometer system based on designed completed The utilizes technique large bandwidth high sensitivity, miniaturization achieved through an chip. By performing single-frequency test...

Abstract This paper aims to explore the feasibility and stability of negative oxygen ions (NOI) shunting based on direct current (DC) pulsating co-frequency coupled electric field method, safeness under a high anion concentration. Negative were obtained corona discharge from voltage, method which was employed detach neutral gas executed with an uncoupled field. In field, exported same derived ion emission polar as guiding polar, while another outlet; purity NOI powered separately is control...

In this paper, a novel broadband lumped-element quadrature hybrid MMIC for interferometric correlation radiometer is proposed. First, the cause of bandwidth limitation in branch-line coupler analyzed, which two identical parallel branches have same frequency response leading to reinforced resonance and narrow band. order reduce such unfavorable superposition effect, with opposite responses are used, exhibits characteristic similar rat-race coupler. To realize hybrid, phase-shifting network...

An eight-channel phased array (PA) radiometer front-end is developed to serve video-rate passive millimeter wave (PMMW) imaging at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}$ </tex-math></inline-formula> -band. The implemented by multichip module (MCM), in which all active microwave functions are realized with GaAs monolithic integrated circuits (MMICs) while devices and connection lines designed...

The analysis, design and measurement of a Monolithic Microwave Integrated Circuit (MMIC) analog phase shifter is implemented based on 0.15 $\mu$m GaAs pHEMT process. We propose flexible methodology for which utilizes multistage cascaded shifting sections. equivalent circuit model the diode established characteristic section analyzed. By adjusting selecting appropriate number stages, desired overall performance obtained, including over 100° shift range, low nearly constant insertion loss...

In this paper, the design and measurement of a Ka-band (32-36 GHz) analog complex correlator based on integrated six-port chip for human body temperature are described. The designed uses add-and-square method by employing distribution network zero-bias Schottky diodes. Moreover, chip, which integrates amplifiers, phase shifters, circuit, is applied in to realize compact size. To verify characteristics correlator, single-frequency test with different input power levels sweep-frequency fixed...