Jeffrey S. Fu

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The ground plane affects the characteristics of a planar inverted-F antenna (PIFA) significantly. Using the idea of the high-impedance surface to construct the ground plane, a new type of compact PIFA with a photonic bandgap type (PBG-type) ground plane is proposed. Both the traditional PIFA and the proposed antenna are analyzed using the finite-difference(More)
New low pass filters with ultra-wide stopband by using dumbbell defected ground structures (DGSs) with size reduction are presented in this paper. Non-uniform DGSs etched under a stepped-impedance microstrip line are developped to get better filter performances of transmission zeros, enhanced return loss and ultra-wide stopband that is beneficial to higher(More)
Measurement and simulation of microwave noise transient of InP/InGaAs DHBT with polyimide passivation is reported in this paper for the first time and is believed to contribute to the overall broadband shot noise. This work provides a better insight into the noise transient mechanism of InP HBTs due to polyimide passivation and can be used to improve the(More)
This letter proposes a new divide-by-2 pHEMT injection locked frequency divider (ILFD) fabricated by 0.5-μm GaAs ED-Mode pHEMTs process and describes the operation principle of the dual-transformer ILFD. First transformer was applied to replace two inductors of cross-couple LC-tank oscillator circuit. The injection signal of ILFD transmits into a transistor(More)
In this paper, we present the low noise amplifier using new feedback connection configurations. The UWB LNA is design in 0.18 m TSMC CMOS technique to achieve high gain, small size and low noise. The LNA achieved 11 dB of average power gain, low 2.87 dB noise figure (NF), -10.9 dB input match, -7 dB return loss, -3 dBm of IIP3 and only 0.54 mm size with 15(More)
A coplanar waveguide (CPW) mode 20–35GHz quadrature coupler has been demonstrated in this study. Good microwave performance and compact size can be achieved simultaneously. The measured return loss is better than 16.6 dB and insertion loss of S21 and S31 are 3.6 0.2 dB. The measured phase difference is 88 2 ± ± o from 20 to 35 GHz. Total chip size including(More)