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Zhang F.,Nanjing University of Aeronautics and Astronautics | Zhang F.,Science and Technology on Monolithic Integrated Circuits and Modules Laboratory | Gao B.,Nanjing University of Aeronautics and Astronautics | Zhou P.,Nanjing University of Aeronautics and Astronautics | Pan S.,Nanjing University of Aeronautics and Astronautics
IEEE Photonics Technology Letters | Year: 2016

A novel triangular pulse generator is proposed based on a polarization multiplexed optoelectronic oscillator (OEO). Employing a dual-polarization modulator, the proposed OEO can simultaneously oscillate at two frequencies of $f$ and $3f$ along the two orthogonal polarizations of the same optical carrier. Thanks to the harmonic injection coupling between the two OEO oscillations, the generated two signals have an exact frequency ratio of 1:3 and can be tuned to be in phase with each other. By properly setting the amplitudes of the two signals, a triangular pulse train can be generated. The generation of a 4.44-GHz triangular pulse train is experimentally demonstrated. A very clean electrical spectrum incorporating the 4.44- and 13.32-GHz components is obtained, and the two tones have good phase noises of -100.6 dBc/Hz at 10 kHz and -99.2 dBc/Hz at 10 kHz, respectively. The generated triangular waveform is very close to an ideal waveform, and the root-mean-square error between the generated and the ideal waveforms is 5.145× 10-4. © 1989-2012 IEEE.


Chu P.,Nanjing Southeast University | Hong W.,Nanjing Southeast University | Dai L.,Nanjing Southeast University | Tang H.,Nanjing Southeast University | And 6 more authors.
IEEE Transactions on Microwave Theory and Techniques | Year: 2014

In this paper, a novel planar bandpass filter is proposed, designed, and implemented with a hybrid structure of substrate integrated waveguide (SIW) and coplanar waveguide (CPW), which has the advantages of good passband and stopband performance inherited from SIW and miniaturized size accompanying with the CPW. Additional design flexibility is introduced by the hybrid structure for efficiently controlling the mixed electric and magnetic coupling, and then planar bandpass filters with controllable transmission zeros and quasi-elliptic response can be achieved. Several prototypes with single and dual SIW cavities are fabricated. The measured results verified the performance of the proposed planar bandpass filters, such as low passband insertion loss, sharp roll-off characteristics at transition band, etc. © 2014 IEEE.


Jiang L.L.,Nanjing Electronic Devices Institute | Jia S.X.,Nanjing Electronic Devices Institute | Zhu J.,Science and Technology on Monolithic Integrated Circuits and Modules Laboratory
Key Engineering Materials | Year: 2013

In this paper the oxygen plasma dry release process for membrane-bridge RF MEMS switches is studied and several methods are used to improve the dry release process. The residual PR (Photoresist) on the device substrate after different process time are observed and measured in this paper. The measured data shows that the residual PR exponentially reduces with etch time. It is found that the residual PR on the bottom surface of the membrane bridge is more than that on the substrate. The completely released RF MEMS switch using oxygen plasma dry etch process is obtained. © 2013 Trans Tech Publications Ltd, Switzerland.


Chu P.,Nanjing Southeast University | Hong W.,Nanjing Southeast University | Wang K.,University of Montreal | Tang H.,Nanjing Southeast University | And 5 more authors.
IEEE Transactions on Microwave Theory and Techniques | Year: 2014

A novel balanced filter realized in the form of substrate integrated waveguide (SIW) is proposed and studied in this paper. Based on the inherently horizontal and vertical symmetry of the SIW, this filter presents inherently high-performance balanced property with advantages of no identical pair requirement, being free from the limitation of symmetrical topology, easy and flexible design, high common-mode (CM) suppression, and robust CM suppression when comparing with conventional counterparts. Several prototypes are designed, fabricated, and measured to verify the expected properties. © 1963-2012 IEEE.


Zhang P.,Nanjing Electronic Devices Institute | Zhu J.,Nanjing Electronic Devices Institute | Zhu J.,Science and Technology on Monolithic Integrated Circuits and Modules Laboratory | Jiang L.,Nanjing Electronic Devices Institute
Guti Dianzixue Yanjiu Yu Jinzhan/Research and Progress of Solid State Electronics | Year: 2014

This article focuses on the relationship between the temperature and the performance of the cantilever RF-MEMS switches. Their performances are first measured at room temperature (25°C) and measured again after they are stored in an oven at a certain temperature T (every other 50°C from 50°C to 200°C) for about one hour followed by cooling down to room temperature outside of the oven. The experiment results indicate that the influence of temperature on the RF performance of MEMS switch is negligible, but its influence on the actuation voltage is susceptible. The distortion of the cantilever is thought to be the main reason for the variation of the actuation voltage. Some methods are proposed at the end of the article to improve the stability of the RF-MEMS switches over temperature.

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