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SAR Tomography processing by using multiple SAR images can create a 3-D image including the height distribution of scatterers. The height estimation can be realized assuming that the multi-baseline observation data as an array data in the DOA (direction of arrival) estimation methods. Orbit error in observation might cause DOA/height errors in imaging results; therefore, calibration of orbits or equivalent...
The one-body 2-D Beam-switching Butler Matrix and the 2-D Beam-switching Rotman Lens are compared. Those are designed to have sixteen 2-D arranged beams. Comparing the proposed Butler matrix with the Rotman lens, it has the low transmission loss, the high uniformity of distributed beams, and the small size. However when the number of 2-D arranged beams is increased, the size of the Butler matrix is...
We presents characteristics of a free access transmission line consisting of a paper substrate and foam instead of dielectric substrate for easy installation in body area network applications. In this paper, we simulated the coupling characteristics between two dipole antennas above the proposed transmission line to show its basic performance. The average of coupling characteristics above the transmission...
A miniaturized Quad band-notch co-planar waveguide (CPW) ultrawideband (UWB) antenna is presented in this paper. The band-notch characteristics around S-band (2.70–3.10 GHz) and downlink C-band (3.70–4.20 GHz) are realized by etching meander-line and horizontal slot in radiating patch. Furthermore, by adding an extended stub and L-shaped slot on ground plane of the antenna, rejection in WLAN (4.90–5...
In this paper, a non-Foster circuit for achieving a negative small capacitance based on Linvill floating-type Negative Impedance Convertor (NIC) is realized. The effect of the parasitic elements and the transmission lines on the circuit performance is discussed. The experimental results show that the circuit presents a negative capacitor of 0.87pF in the UHF band. The circuit linearity test reveals...
In this paper, a hybrid Z-shaped dielectric resonator antenna (DRA) design is proposed. Conformai strip feeding is utilized to feed the antenna. It is observed that by use of two different DRA materials, Q-factor can be reduced and in turn ultrawide bandwidth (UWB) can be achieved. A rigorous parametric study is carried out to optimize the bandwidth of proposed antenna while maintaining its compactness...
A method for widening bandwidth of a planar slot antenna is proposed. This method only requires a short strip in a rectangular aperture of slot antenna. By using this uncomplicated method, we achieved relative bandwidth up to 55.5% for |S11|≤0.5(VSWR≤3). Additionally, the gain of the antenna shows stability for frequency in the bandwidth. These results indicate that a short strip generate a second...
This paper investigates the effectiveness of the edge folded frequency selective reflector (FSR) structure in reducing mutual influence between low and high band radiation patterns of a dual band reflector backed dipole antenna (RBDA), which employs FSR in the high band RBDA. As the results of the moment method analysis related to the half-power-beamwidth (HPBW) and the front-to-back ratio (FB) characteristics...
A metal-frame inverted-F antenna for the metal-casing smartphone is presented. The antenna is formed by two inverted-F Antenna (IFA) structures to cover 824–960 MHz (low band), 1710–2690 MHz (middle band), and 3400–3600 MHz (high band). The antenna for the metal-casing smartphone has a narrow metal clearance of 2 mm. The feeding and shorting strips with matching networks for the two IFAs are disposed...
This paper presents a dual-band frequency-tunable single-layer multi-ring microstrip antenna (MR-MSA) fed by an L-probe with varactor diodes. In order to develop a frequency-tunable multiband planar antenna, two split ring patches with two varactor diodes mounted on each ring patch are arranged concentrically on a dielectric substrate. An L-shaped feeding probe arranged in the same layer as the ring...
CISPR25 test is used to characterize EMC performance of automotive component. To avoid miss detection of unwanted emission in this test, it is necessary to scan the measurement antenna along the wire. In this paper, we propose a no scanning method using two loop antennas placed near DUT and wire terminal. Simulation and measurement show that the proposed method picks up unwanted signal with the errors...
In free-space material measurements, it is known that the minimum size of a planar MUT (Material Under Test) should be larger than three times the beam waist of the antenna to neglect diffraction effects at the edges of the MUT. To hold the MUT, its holder has the aperture size larger than the minimum MUT size. In the case of metal MUT holders, even though their aperture size is larger than three...
Indoor use wireless telecommunication systems such as WLANs (Wireless Local Area Networks) or UHF-RFID (Radio Frequency Identification) are becoming increasingly popular. The indoor telecommunication environment is deteriorated by multiple reflection interference. The ultrathin microwave absorber in consideration of indoor use is developed for reduction of the multiple reflection. Unfortunately, this...
The height profiles of rain drop size distribution have been studied to understand the role of the vertical drift velocity in the atmospheric boundary layer in changing drop number densities at different heights during convective rain events. The observations with a micro rain radar (MRR) over Kolkata, a tropical location, of rain events pertaining to the period of 2011–15 have been analyzed. A prominent...
In this paper, we propose a sensing antenna for detecting leaks in pressurized pipes or industrial storage tanks with a simple passive on-chip network. The chip, fabricated using the integrated passive device (IPD) process, is composed of a section of dual-operational mode synthesized transmission line. The electrical properties of the synthesized line are a function of the material medium surrounding...
Methods such as branching of the antenna element and meandering into a spiral are typically proposed for achieving dual-band quadrifilar helical antennas (QHAs). However, these methods suffer from drawbacks such as radiation pattern degradation of the antennas and a large number of design parameters. This paper proposes a dual-band QHA whose simple structure is realized by applying a parallel resonance...
The proposed antenna structure with modified ground plane that fully covers Bluetooth and Wireless Fidelity (Wi-Fi) applications. In order to enhance the efficiency, a resonator which consists of a closed loop of a ground plane and lumped inductor (L) are proposed. The closed loop is connected to the ground plane with open-end extension by lumped inductor for easy control. This antenna designed on...
Recentry, interference of artificial noises from electrical power transfer becomes large and deterioration of sound quality of AM radio is worried. The authors proposed a noise suppression system for AM radio using quadrature demodulation and PI algorithm. It is expected that the noise suppression effect is reduced when the system has a synchronization error. In this paper, an effect of synchronization...
A microwave radar system is a useful tool for all-weather type remote sensing, such as terrain surface measurement. It is well known fact that a resolution of time-of-arrival (TOA) is strictly determined by the frequency bandwidth of transmitted signal. As super-resolution technique beyond such limitation, a compressed sensing (CS) algorithm has come under spotlight because a sparse assumption is...
The fifth-generation (5G) mobile communication systems will benefit immensely with the extension of their operation to mmWave bands. To this end, understanding the system-level performance of mmWave cellular networks carries critical importance. In this paper, we investigate the average signal-to-interference plus noise ratio (SINR) distribution (geometry) performance for indoor and outdoor mobile...
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