A compact monopulse comparator with complete nulling in all DELTA channels is designed and fabricated. The proposed comparator has small dimension and consists of interconnections of four broadband branch-line couplers and several 90° phase shifters with multistage Schiffman coupled-lines. This comparator has been characterized by its eight-port -parameters to generate the SUM and DELTA channel fr

This paper investigates metamaterials composed of resonant particles with negative electric polarizability located in a three-dimensional net. The main problem in fabricating these materials is the spread of the resonant frequencies of particular planar resonators. This spread is caused by the tolerances of the fabrication process for planar resonators. The simulation shows that there is a limit t

In recent years, millimeter wave (MMW) has received tremendous interest among researchers, which offers systems with high data rate communication, portability, and finer resolution. The design of the antenna at MMWs is challenging as it suffers from fabrication and measurement complexities due to associated smaller dimensions. Current state-of-the-art MMW dual-band antenna techniques demand high p

In this paper, a 3 dB -plane substrate-integrated waveguide (SIW) power divider/combiner with improved isolation is reported. By adding two isolated ports into the Y-junction, it will perform like a multi-port coupler, so that the isolation between its dividing ports can be effectively improved as the newly-added ports are properly matched. To verify the availability and effectiveness of this conc

Design and fabrication of a microstrip feedline-based Vivaldi antenna in the frequency range of 6.0?8.0 GHz have been presented. The Vivaldi antenna is a planar antenna, fabricated at the microstrip feedline by having an exponentially tapered slot profile on it. An optimized computer-aided design has been developed and simulated for the desired radiation parameters like voltage standing wave ratio

The Misell algorithm is one of the most widely used phase retrieval holography methods for large reflector antennas to measure surface deformation. However, it usually locks in a local minimum because it heads downhill from an initial estimation without any consideration whether it heads for a global minimum or not. The core problem of the Misell algorithm is to find an initial estimation near the

A compact printed reconfigurable monopole antenna with switchable band-notches is designed and manufactured. The proposed antenna mainly consists of a disc-like radiator with two pairs of T-shaped strips protruded inside a rectangular aperture. Five PIN diode switches are employed to bridge or open the slots, which allow the antenna to be configured into three different structures functioning as a

This paper investigates a wideband and low axial ratio circularly polarized (CP) antenna, which is composed of a monopole on a novel polarization rotating reflective surface (PRRS) based on a corner-truncated artificial magnetic conductor (AMC) structure. By adjusting the dimensions of truncated corner properly, the PRRS has two polarization rotation (PR) frequency points. Then, a large PR band of

In this study, wideband bandpass power divider with good out-of-band performance is proposed. Two bandpass filters (BPFs) are utilized to substitute the quarter-wavelength transmission line in conventional Wilkinson power divider. A resistor is specially arranged between two BPFs for a good isolation. Four transmission zeros (TZs) are found to be distributed in the lower and upper stopband of the

The next generation of wireless networks (5G) employs directional transmission at millimeter wave (mmW) frequencies to provide higher bandwidth and faster data rates. This is achieved by applying antenna arrays with proper beam steering capabilities. Rotman lens has long been used as a lens-based beamformer in electronically scanned arrays and its efficient design is important in the overall perfo