Loading [MathJax]/extensions/MathMenu.js
Xiaoguo Huang - IEEE Xplore Author Profile

Showing 1-21 of 21 results

Filter Results

Show

Results

In this paper, a novel mixed coupling tunable LC bandpass filter (BPF) with constant bandwidth is proposed. The introduction of the magnetic-dominant mixed coupling topology can not only generate transmission zeros for strong out-of-band rejection, but also compensate for bandwidth to achieve constant bandwidth while tuning. Measurement results show that the central frequency tuning range of desig...Show More
The paper realizes the estimation of the vector characteristics of the circulator leakage channel for in-band full-duplex self-interference cancellation system based on software defined radio technique. The magnitude and phase responses of the circulator leakage channel are measured by using FFT and cross-correlation algorithm, respectively. USRP B210 and GNU Radio are used for the demonstration. ...Show More
In this paper, the tuning range and quality of four types of varactor-loaded resonators, varactor-loaded λ/2 resonator, varactor-loaded λ/4 resonator, varacor-loaded open-loop resonator, and dual-varactor-loaded resonator, are analyzed. To verify the varactor-loaded λ/4 resonator has largest tuning range and the varactor-loaded λ/2 resonator has largest quality, a dual-band banstop filter based du...Show More
Rydberg atoms are atoms in their highly excited energy states. The physical properties of Rydberg atoms in the presence of external fields play an important role in quantum precision measurement. In recent years, radio-frequency electric field sensing based on Rydberg atoms has attracted significant interest. It is widely recognized as an electromagnetic sensing system fundamentally different from...Show More
The paper proposes a self-interference cancellation (SIC) architecture based on unequal power divider. The transmission efficiency of SIC is investigated. A power divider with unequal power dividing ratio is used in the SIC for improving transmission efficiency of circulator isolated transceiver. A four-tap SIC circuit was designed and fabricated. Measurement results show that 60dB isolation is ac...Show More
In this article, the realization of concurrent multifunction in phased array full-duplex platforms is discussed. For modern complex electromagnetic environment, an efficient architecture is needed to accomplish the concurrent working of several different functions, such as communication, radar, spectrum sensing and so on. First, we establish a novel architecture based on the phased array system to...Show More
Full-duplex, which aims to simultaneously transmitting and receiving over the same band, together with phased array antennas play fundamental roles in next-generation wireless communication systems. The combination of them, phased array fullduplex, is widely accepted as a promising way for realizing practical full-duplex communications. However, diversified application scenarios and rapidly grown ...Show More
A novel cascade trisection (CT) coupling structure based on half-wavelength resonators is proposed for designing constant absolute bandwidth (CABW) tunable bandpass filters. Third-order tunable bandpass filter (BPF) which can realize CABW and a high side cross coupling transmission zero (Tz) is designed based on the proposed CT structure. Measurement results show that the central frequency tuning ...Show More
Phase noise is one of the core features in reference frequency source circuits, and directly affects the performance of frequency synthesizer. When a source is used as reference signalits phase noise is transferred to IF signal through down converter circuit, and reduces the signal noise ratio. In multi-channel applications, the number of reference signals should match to the quantity of channels....Show More
This paper presents a tunable dual-band or single-band bandstop filter based on switchable varactor-loaded dual-mode resonator. The proposed tunable filters topologies consist of two switchable dual-mode resonators and main transmission line. When the switch is on, the switchable dual-mode resonator changes to dual-mode resonator, which can be used to design dual-mode tunable bandstop filter; when...Show More
This paper presents a low-voltage CMOS (complementary-metal-oxide-semiconductor) mixer with low power consumption. By using the folded-cascade structure, the problem on high supply voltage of the stacking transconductance-stage and switching-stage is solved. Firstly, a differential cross-coupling structure is used to improve transconductance-stage's linearity without decreasing voltage margin. The...Show More
This paper presents the design and implementation of a tunable bandpass filter with constant absolute bandwidth. Two types of coupled microstrip lines in the anti-parallel and pro-parallel formats with varactor-loaded ⋋/2 resonators are investigated to demonstrate its advanced capacity in control of the bandwidth variation. In this design, two adjacent resonators are coupled with each other throug...Show More
A varactor-based tunable diplexer with wide tuning range is proposed in this paper. The proposed diplexer consists of two varactor-loaded open-loop resonator filters. Size reduction and wide tuning range are achieved by using the varactor-loaded open-loop resonator. A simple microstrip T junction at the input and two filters responsible for the respective passbands is applied. Simulated insertion ...Show More
A new three-dimensional (3-D) tunable bandpass frequency selective structure (FSS) with wide tuning range is presented. The tunable FSS consists of a periodic array of printed circuit boards and a number of inserted metallic plates, where varactor-loaded λ/4 stepped-impedance resonators (SIRs) are constructed based on the propagation mode excited in the structure. By properly choosing the impedanc...Show More
In this paper, a tunable bandstop filter with constant absolute bandwidth is proposed based on electric coupling compensation of tunable capacitor network. The equivalent circuit model of the tunable capacitor network is presented to study the tunable mechanism. The electric coupling factor of the tunable capacitor network increases while the tunable capacitor increasing. This mechanism can be use...Show More
A high-selectivity dual-band bandpass filter using a modified triple-mode resonator with two paralleled stubs is proposed. By adding a coplanar waveguide (CPW) structure into a microstrip dual-mode stepped-impedance resonator (SIR), the triple-mode resonator is achieved without significantly increasing the overall circuit size. Five transmission zeros are generated in the desired band so as to imp...Show More
This paper presents a novel procedure to the design of independent tunable dual-band bandpass filters with constant absolute 3-dB bandwidths. Only two bias voltages are required to control the locations of the passbands, respectively. Two kinds of dual-mode resonators are proposed to be selected while designing the passbands. Based on different parameters of even- and odd-modes, there are four typ...Show More
This paper presents a new type of lager tuning rate tunable filters using varactor-loaded open-loop resonators. The filter is based on capacitively loaded folded λ/2 resonators that are coupled to each other with mixed electrical and magnetic coupling. By adjusting the value of the varactors between the open gaps in a mixed coupled filter, the coupling coefficients and external quality can be tune...Show More
This paper presents a two-pole dual-band tunable bandpass filter (BPF) with independently controllable dual passbands based on a novel tunable dual-mode resonator. This resonator principally comprises a λ/2 resonator and two varactor diodes. One varactor is placed at the center of the resonator to determine the dominant even-mode resonant frequency; the other is installed between two ends of the r...Show More
In this paper, two- and three-pole microstrip LC constant fractional bandwidth (CFBW) and constant absolute bandwidth (CABW) tunable bandpass filters are proposed. The equivalent-circuit models are presented to study the tunable mechanism. The filter can be reconfigured by changing the capacitance of the LC resonators. Based on electric coupling coefficient compensation, second- and third-order tu...Show More
In this letter, a novel quadruple-mode resonator bandpass filter (BPF) with tunable bandwidth is proposed. By using two types of microwave varactors to tune the resonant frequencies and transmission zeros (TZs), the high-side edge of the passband and low-side edge of the passband can be separately varied. Therefore, the bandwidth could be tunable with reasonable adjust of the values of varactors. ...Show More