Previously reported quasi-optical amplifier arrays have limited bandwidth and suffer from poor input/output isolation. These prsbllems can be solved by using traveling wave antennas and distributed amplifier techniques. FII'TD simulations of a linearly tapered slot array topology demonstrate very broadband quasioptical transitions are feasible with small unitcell aperture. Experiments using a s...

In this paper, an ultra-wide rejection bandwidth compact microstrip low-pass filter with low insertion loss using two identical etched shapes in the ground plane and a compensated line is investigated. Its circuit model is as well presented. The proposed filter offers a low insertion loss of 0.1 dB and ultra-wide rejection bandwidth of more than 20 dB up to 20 GHz. The simulated results are fou...

technology. They can be made on-chip along with an amplifier, mixer, multiplier, or other active circuit, or they can be printed separately on a ceramic substrate like alumina. The latter approach is usually most economical since real estate on III-V semiconductor wafers is costly compared to that of passive substrates, and they can easily be packaged alongside other MMICs and connected with bo...

This paper proposes a two way L and S band Gysel power divider/combiner that uses line to ground resistors. Step by step methods to obtain a wide isolation and transmission bandwidth are presented. A design that uses five resistors is selected and optimized based on Quasi Newton method. Then the Defected Microstrip Structure (DMS) and Defected Ground Structure (DGS) is used to obtain better tra...

The design of Cyclotron CYCHU-10 has been carried out at Huazhong University of Science and Technology (HUST). Because of the low centre frequency (99MHz) of its RF system, we should choose suitable directional couplers for the RF system which is supposed to be highdirectivity and tight-structure. This paper analyzes and synthesizes kinds of directional couplers, especially microstrip structure...

Crosstalk is an important problem in high-speed printed circuit board design which is one of the signal integrity issues. A wildly used theoretical model based on microstrip theory is presented in this paper. On this basis, the origin and the factors affecting crosstalk are introduced. Cadence Allegro is used to analyze these factors. Key-words: Signal integrity, crosstalk, aggressor line, vict...

In this paper, a novel type of dual-band bandpass filter (DBBPF) is proposed by using microstrip composite resonators, and its design method is developed based on the lumped-element equivalent circuit of the filter. Both the midband frequencies and the passband widths of the dual bands of the filter can be controlled separately. Four DBBPFs with different specifications are designed, fabricated...

We present a novel design framework for microwave circuits. We calibrate coarse models (circuit based models) to align with fine models (full-wave electromagnetic simulations) by allowing some preassigned parameters (which are not used in optimization) to change in some components of the coarse model. Our expanded space-mapping design-framework (ESMDF) algorithm establishes a sparse mapping fro...

A theoretical analysis of a gap-coupled stacked annular ring microstrip antenna with superstrate is performed in order to obtain wider bandwidth operation. The effects of air gap, superstrate thickness and feeding point location on the antenna performance are analyzed in TM11 mode using equivalent circuit concept. It is noted that the proposed antenna is very sensitive to the feeding point loca...

In the present paper, design and analysis of a 2.4 GHz printed dipole antenna for wireless communication applications are presented. Measurements on return loss and radiation pattern of this antenna configuration are included in this investigation. The printed dipole is combined with the feeding structure of a microstrip via-hole balun and is fabricated on an FR-4 printed-circuit-board substrat...