Chong-hu Cheng

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An improved frequency notched ultrawideband (UWB) microstrip slot antenna with a square ring resonator embedded in the tuning stub is proposed. The antenna is investigated numerically and experimentally for its impedance matching property, frequency notched characteristic and radiation performance in detail. As will be reported, compared with conventional(More)
A printed diversity antenna for ultra-wideband applications is proposed. The proposed antenna is composed of two square monopoles. In order to reduce the mutual coupling between the two elements, A cross shape stub is introduced. The antenna has been investigated numerically. As is reported, the operation bandwidth of the antenna is from 3.3 GHz to 10.5(More)
A printed diversity antenna for Ultra-wideband applications is proposed. The proposed antenna is composed of two elliptical shape monopoles. Two stubs and a slot are introduced to reduce the mutual coupling between the two elements. The antenna has been investigated numerically and experimentally. As the results show that the operation bandwidth of the(More)
A compact diversity antenna for Ultra-wideband applications is proposed. The proposed antenna is composed of two square monopoles. In order to reduce the mutual coupling between the two elements, A T shape stub is introduced. The antenna has been investigated numerically. As is reported, the operation bandwidth of the antenna is from 3.3GHz to 10.4GHz. Good(More)
A wide upper stopband and nonorthogonal input/output (I/O) feed dual-mode bandpass filter (BPF) is proposed. The BPF is implemented in a 2-layer low temperature co-fired ceramic (LTCC) substrate and the wide upper stopband is achieved using broadside parallel-coupled lines with stepped impedance feed lines. 40 dB suppression of a 2<sup>nd</sup> harmonic(More)
In this paper, a new class of wideband phase shifters on multimode resonator is proposed and developed. Compared with its conventional counterparts, these new phase shifters have a few advantageous features such as simple structure, intrinsic wideband characteristic, large phase-shift value, and easy adjustment in phase shift. The phase properties of(More)
This paper proposes a compact and miniaturized branch-line coupler using a crossing bond wire structured slow-wave branch line (CBWSWB). The proposed coupler achieves a size reduction of 82% compared with a conventional implementation. Measured S11, S21, S31 and S41 of the proposed coupler are better than −24, −3.7, −3.7 and −28 dB at 3GHz, respectively.(More)
Tuning space mapping (TSM) with tuning exponent parameter of ABCD-Matrix is proposed and verified. A section of design interest in the electromagnetic (EM) model is replaced by &#x2018;n&#x2019; pieces cascaded ABCD-Matrixes, and each ABCD-Matrix is the EM-simulated ABCD-parameter of pre-assigned cell circuit (PCC). Finally the optimal exponent parameter of(More)
A compact lumped-element low temperature co-fired ceramic (LTCC) quadrature hybrid with harmonics suppression is proposed. The proposed topology enables significant circuit size reduction using spiral inductors with orthogonal input/output ports and vertical interdigital capacitors (VICs) placed in center of the hybrid. The overall size of the LTCC hybrid(More)
A compact narrow-band low temperature co-fired ceramic (LTCC) filter with a fractional bandwidth of 3% is proposed. The proposed filter consists of five cascaded half-wavelength resonators vertically arrayed on each LTCC layer. End-coupling between adjacent resonators is precisely controlled by rectangle-shaped slot on intermediate ground layer. The overall(More)