An active microstrip antenna array with dual switching beams were developed and demonstrated. The array contained several active antennas and an extra amplifier-embedded coupling (microstrip) line. Two injection-locking signals were used in the design, that is, the free-space mutual coupling between antennas and the injection signal on the coupling line tapped from the first oscillator in the a...

The embedded meander line in stepped-impedance resonator (SIR) is proposed to design narrow bandpass filter with a good stopband characteristics. The design differs from the general SIR configuration in that the microstrip lines are bent at the location of the maximum magnetic field density. As a result, the resonators have high external quality factors by themselves, since the factor is closel...

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...

The paper presents the performances of microstrip patch antennas excited by the aperture-coupling feed that is composed of a T-shaped microstrip feed line and an annular-ring slot. Because the annular-ring slot is designed at a full-wavelength resonant mode, a broad impedance bandwidth can be obtained by combing the resonant modes of the coupling slot and radiating patch; moreover, a low cross ...

In this paper, a novel wideband microstrip-fed quasi-Yagi antenna is presented. The proposed quasi-Yagi antenna consists of a microstrip-fed monopole, three radiating patches (two square patches and a rectangular patch), and three parasitic strip elements as the function of reflector. In order to achieve wide bandwidth, two parasitical patches are etched on both sides of the substrate. Furtherm...

A branch-line coupler (BLC) working at two arbitrary frequencies using CRLH transmission lines (TLs) is presented. It is demonstrated that the two operating frequencies can be obtained by tuning the phase slope of the different line sections. A prototype is demonstrated using only microstrip technology.

A novel ultra wideband band (UWB) bandpass filter is developed using ground plane aperture technique for enhancement of the capacitive coupling in the parallelcoupled microstrip line (PCML). The PCML with two external lines is characterized by an equivalent J-inverter network with its susceptance and the two electrical line lengths.