Browsing by Author "Chi, Chun-Hsiang"

Now showing 1 - 7 of 7

A 10-110 GHz fundamental/harmonic rat-race mixer
(2007)
Chi, Chun-Hsiang
;
Wu, Chung-Hung
;
Wang, Wei-Ting
;
Lai, Chi-Hau
;
Niu, Dow-Chih
This paper describes a broadband 10-110GHz mm-wave rat-race ring diode mixer. The mixer can be used as a fundamental mixer as well as a harmonic mixer. The finite-ground-width CPW on a 15mil alumina substrate is used to implement the circuit. The mixer is designed to allow DC bias that a local power as low as 0dBm could properly pump the mixer. Two commercial available M/A-Com MA4E2037 GaAs beam-leaded Schottky diodes are used. The measured conversion loss is typically 9dB from 10 to 100GRz in the fundamental mixing mode and 15dB from 20 to 110GRz in the harmonic mixing mode.
A compact wideband 180 degrees hybrid ring coupler using a novel interdigital CPS inverter
(2007)
Chi, Chun-Hsiang
;
Chang, Chi-Yang
;
電信工程研究所
;
Institute of Communications Engineering
This paper proposes a stepped-impedance wideband 180 degrees hybrid ring coupler with a novel frequency-independent 180 degrees phase inverter implemented by interdigital coplanar strip (CTS). Simple design equations for stepped-impedance lines and design curves for CTS/interdigital CTS are also presented. Due to the combination of a stepped-impedance structure and an ideal phase inverter, the proposed hybrid achieves size reduction, wide bandwidth, and excellent phase and amplitude performance. The size of this hybrid is about 13% of the conventional one. Experimental results show that this hybrid ring coupler centered at 2 GHz has a 10-dB return loss bandwidth of 97.5% from 0.98 to 2.93 GHz with 0.5 dB amplitude imbalance and 30 phase imbalance for both out-of-phase and in-phase operation. Its isolation is better than 30 dB from 0.5 to 4 GHz.
A wideband bandpass filter with wide upper stopband using stepped-impedance cascadable 180 degrees hybrid rings
(2007-08-01)
Chi, Chun-Hsiang
;
Chang, Chi-Yang
;
電信工程研究所
;
Institute of Communications Engineering
This letter proposes a wideband bandpass filter by cascading two 3-dB stepped-impedance. cascadable 180 degrees hybrid rings with a pair of stepped-impedance lines. Thanks to the stepped-impedance lines, a broad upper stopband is achieved. The stepped-impedance vertically installed planar (VIP) coupler is used to implement the ideal 180 degrees phase inverter and crossovers. The experimental results show that this 2-GHz center frequency, fourth order filter has a 10-dB return loss bandwidth of 92.5% and upper stopband rejection levels of better than -20 dB up to 6.8, GHz. This proposed filter achieves wide passband and broad stopband performance simultaneously.
A wideband CPS bandpass filter with ultra-wide upper stopband using stepped-impedance rat-race hybrid couplers
(2007)
Chi, Chun-Hsiang
;
Chang, Chi-Yang
;
電信工程研究所
;
Institute of Communications Engineering
A wideband coplanar strip (CPS) bandpass filter using two 3-dB stepped-impedance rat-race hybrid couplers is proposed in this paper. The stepped-impedance structure results in both ultra-wide upper stopband and size reduction. The low impedance and high impedance CPS lines are realized using the interdigital structure for low impedance and conventional structure for high impedance, respectively. The ideal phase inverter has been implemented with hybrid CPS/interdigital CPS structure. Experimental results show that this 2-GHz fifth order filter depicts a 10-dB return loss bandwidth of 100% and upper stopband rejection levels of better than -40dB up to 17.5 GHz. This proposed filter achieves wide passband and ultra-wide stopband performance simultaneously. This filter is fabricated using CPS on 15-mil Al(2)O(3) substrate with a dielectric constant of 9.8. The measured results agree well with the simulated results.
Miniaturized Hybrid Ring Bandpass Filter with a Notched Band and an Improved Upper Stopband Using Double-Sided Parallel-Strip Lines
(2012)
Li, Jian-Yu
;
Chi, Chun-Hsiang
;
Chang, Chi-Yang
;
電信工程研究所
;
Institute of Communications Engineering
A wideband stepped-impedance hybrid bandpass filter with a notched band and an improved upper stopband is proposed. The double-sided parallel-strip line (DSPSL) is employed to implement the proposed filter. The stepped-impedance structure improves the upper stopband performance and reduces the size. Besides, the open-circuited stub embedded in the stepped-impedance line of the hybrid ring is used to create a notched band. The low impedance portion of the stepped-impedance line is formed by the DSPSL while the high impedance portion of that is constructed by the offset double-sided parallel-strip line (ODSPSL). The design example is fabricated on a 20 mil RO4003 substrate. The measurement results show excellent agreements with the electromagnetic simulation.
Synthesis and Design of Generalized Chebyshev Wideband Hybrid Ring Based Bandpass Filters With a Controllable Transmission Zero Pair
(2010-12-01)
Li, Jian-Yu
;
Chi, Chun-Hsiang
;
Chang, Chi-Yang
;
電信工程研究所
;
Institute of Communications Engineering
A systematic and analytical method for the exact synthesis of generalized Chebyshev wideband hybrid ring based bandpass filters with a controllable transmission zero pair is developed in this paper. The basic configuration of the proposed filters consists of a hybrid ring, a multi-section short-circuited stub and a multi-section open-circuit stub. In this configuration, the position of the controllable transmission zero pair can be easily designed by setting the impedances of the multi-section short-circuited stub and the multi-section open-circuit stub. According to the position of the controllable transmission zero pair, two kinds of filters are proposed. The filter has a controllable transmission zero pair on the real axis (imaginary frequency) that they can be arranged to improve the group delay flatness. On the other hand, the filter has a controllable transmission zero pair on the imaginary axis (real frequency) and the desired stopband suppression can be obtained by adjusting the optimal position of them. This synthesis method is developed to obtain the impedance value of each line section and ripple factors of the filters with respect to given specifications (center frequency, passband bandwidth and transmission zeros). Two design examples, the fifth-order filter with a controllable imaginary frequency transmission zero pair and the fifth-order filter with a controllable real frequency transmission zero pair, are synthesized and fabricated. The measured results validate and confirm the theoretical predictions.
Synthesis of Wideband Bandpass Filters Using a Hybrid Ring Shunts with an Open-circuited Stub
(2011)
Li, Jian-Yu
;
Chi, Chun-Hsiang
;
Chang, Chi-Yang
;
電信工程研究所
;
Institute of Communications Engineering
Wideband bandpass filters using a hybrid ring with a shunt open-circuited stub is proposed and developed. The impedances of the hybrid ring and open-circuited stub determine the location of the transmission zero pair in the bandpass domain. This controllable transmission zero pair can be designed to flatten the group delay or improve the selectivity of the filter. Two experimental filters using the same circuit topology are realized to verify the improvement of group delay flatness and selectivity respectively. These two design examples are implemented by balanced microstrip line on a 20-mil RO4003 substrate. The measurement results show excellent agreements with the electromagnetic simulation.