Nanjing Electronic Devices Institute

Nanjing, China

Nanjing Electronic Devices Institute

Nanjing, China

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Sun H.,National University of Singapore | Guo Y.-X.,National University of Singapore | Wang Z.,Nanjing Electronic Devices Institute
IEEE Transactions on Antennas and Propagation | Year: 2013

This communication presents a 60-GHz wideband circularly polarized (CP) U-slot patch antenna array of 4× 4 elements on low temperature cofired ceramic (LTCC). A CP U-slot patch antenna is used as the array element to enhance the impedance bandwidth and a stripline sequential rotation feeding scheme is applied to achieve wide axial ratio (AR) bandwidth. Meanwhile, a grounded coplanar waveguide (GCPW) to stripline transition is designed for probe station measurement. The fabricated antenna array has a dimension of 14× 16× 1.1 mm}3. The simulated and measured impedance bandwidths, AR bandwidths, and radiation patterns are investigated and compared. Measured results show that the proposed antenna array has a wide impedance bandwidth from 50.5 GHz to 67 GHz for vert S} -11} vert < -10∼ dB}, and a wide AR bandwidth from 54 GHz to 65.5 GHz for AR}< 3∼ dB}. In addition, it exhibits a peak gain of 16 dBi and a beam-shaped pattern with 3-dB beam width of 20 circ. Moreover, its AR keeps below 3 dB within the 3-dB beam width. © 1963-2012 IEEE.


Chu H.,National University of Singapore | Chu H.,Nanjing University of Science and Technology | Guo Y.-X.,National University of Singapore | Wang Z.,Nanjing Electronic Devices Institute
IEEE Transactions on Antennas and Propagation | Year: 2013

Wideband 60-GHz vertical off-center dipole antenna and its arrays on low-temperature cofired ceramic substrate are presented in this paper. The dipole antenna is designed using the off-center-fed technology to cover all the four channels defined in 60-GHz standards from 57 to 66 GHz. A 4 \times 4 planar array is optimized to achieve a maximum gain of 15.6 dBi at 60 GHz and above 10.2 dBi in the passband, while a beam-steering array is optimized to give a 5-dB measured beamwidth wider than 80\circ at 60 GHz. Measured results indicate our designs meet the above requirements well and satisfy 60-GHz applications. © 1963-2012 IEEE.


Zhang Z.,Nanjing Southeast University | Liao X.,Nanjing Southeast University | Han L.,Nanjing Southeast University | Cheng Y.,Nanjing Electronic Devices Institute
Sensors and Actuators, A: Physical | Year: 2011

This paper first presents the detection and non-detection function of an inline RF MEMS power sensor by employing two shunt capacitive MEMS switch structures. It solves a problem that regardless of whether the power sensor needed to detect the power, a certain microwave power will always be detected, which results in the unnecessary power loss. This power sensor is based on sensing a certain percentage of the incident microwave power coupled by a MEMS membrane. The effect of an impedance matching structure for improving microwave characteristics, a capacitance compensating structure for obtaining the wideband response, and the two shunt capacitive MEMS switch structures for achieving both states conversion together associated in this sensor, on the performance of the power sensor is proposed in this paper, and verified by the simulation and measurement. This power sensor offers the compatible capability with GaAs MMIC technology. In the detection state, experiments demonstrate that the design of the improved power sensor has resulted in the reflection loss of less than -17 dB, the insertion loss of less than 0.8 dB, and the flatness of the frequency response at X-band. And a sensitivity of more than 36 μV mW-1 and a resolution of 0.316 mW are obtained at 10 GHz under the normal ambient temperature. Yet in the non-detection state, the design has resulted in the reflection loss of less than -19 dB and the insertion loss of less than 0.6 dB. The measured actuation voltage of MEMS switches is about 42 V. © 2011 Elsevier B.V. All rights reserved.


Zhu J.,Nanjing Electronic Devices Institute
Guti Dianzixue Yanjiu Yu Jinzhan/Research and Progress of Solid State Electronics | Year: 2012

The technologies and developments of 3D-stack and TSV (Through silicon via) are introduced. The advantages and disadvantages of W2W (Wafer to wafer) and D2W (Die to wafer) are discussed. The introduction focuses on the key technology of TSV interconnect process. The process flows and features of via first, via middle and via last are presented. The road map and market value of TSV technology are introduced. 3D-stack and TSV have become a hot research field of microelectronics. They are the inevitable trend of microelectronics and MEMS technology and the key technology of hybrid integration microsystem.


Zheng W.,Nanjing Electronic Devices Institute
Guti Dianzixue Yanjiu Yu Jinzhan/Research and Progress of Solid State Electronics | Year: 2012

It is very important to describe FET's large-signal impedance accurately for MMIC design. In order to simulate FET's large signal characteristic, it is necessary to research its gate equivalent capacitance model in the large signal model, especially in high frequency. Based on previous results, the paper deduces a new gate-source/gate-drain capacitance equation. By comparing the loadpull results of a 6×80 μm GaAs PHEMT device, it is shown that the accurate gate equivalent capacitance model improves the precision of FET's large signal model greatly. This helps the research of device model and MMIC design.


Li Y.,Nanjing Electronic Devices Institute
Guti Dianzixue Yanjiu Yu Jinzhan/Research and Progress of Solid State Electronics | Year: 2011

Compared with Silicon, 4H-SiC is a superior material for power devices. With wide band-gap, high thermal conductivity and high critical electric field, 4H-SiC is a good candidate for high-power, high-temperature, high-frequency, low-loss and radiation-hard applications. This paper reviews the development of 4H-SiC material and power device technology for the recent 10 years, with emphasis on the bottle-neck technology problems.


Xue F.,Nanjing Electronic Devices Institute
Guti Dianzixue Yanjiu Yu Jinzhan/Research and Progress of Solid State Electronics | Year: 2015

The various behaviors of traps in HFET were compared in this paper, from which it was found that many behaviors couldn't be interpreted by the tapping of electron in traps from energy band. It was proposed from the large difference of trap density between inner and outer channel that the high density traps in outer channel were not induced by the tapping of electrons in traps. Through self-consistent solving of two dimensional Poisson equation and Schrodinger equation, it was found that a large band deformation was produced between two sides of the strong electric field peak in the gate-drain gap, which made the partial two dimensional electron gases not able to move through the strong electric field peak and some localized electron gases were formed. By using this new concept of localized electron gases, the experimental phenomena of traps in GaN HFET could be interpreted, from which it was proposed that the localized electron gases were mistaken for 'traps' in these trap experiments. A new path to solve the difficult problem for current collapse and reliability in GaN HFET was proposed from the deep investigation of localized electron gases. ©, 2015, NUAA Printing House. All right reserved.


Xue F.,Nanjing Electronic Devices Institute
Guti Dianzixue Yanjiu Yu Jinzhan/Research and Progress of Solid State Electronics | Year: 2015

By ignoring the permeating of the electron wave function into the barrier layer, a new train of thought of solving the Poisson equation to obtain the energy band in barrier layer without electron is proposed. A new method is put forward that the Poisson equation in barrier layer could be solved by treating the polarization charge, impurity charge, and electron charge outside the barrier layer as interface charge at the boundary of barrier layer.The energy band in barrier layer calculated by the Poisson equation agrees with the self-consistent energy band solution. A polynomial of electron density is used to fit the energy level of fundamental sub-band calculated by the self-consistent energy band software, from which a transcendental equation of electron density is derived. For four different heterostructures, the electron density and energy band in barrier layer calculated by the mentioned transcendental equation of electron density agree with the self-consistent energy band solution, from which a new method to self-consistently solve the Poisson equation and Schrodinger equation is established. The interaction between the electron density in channel well and the heterostructure band in barrier layer is investigated by the mentioned Poisson equation in barrier layer, and thus the variation of electron density with the heterostructure in barrier layer is discussed and a new idea of band tailoring is proposed. ©, 2015, NUAA Printing House. All right reserved.


Cheng H.F.,Nanjing Electronic Devices Institute
Applied Mechanics and Materials | Year: 2013

In this paper, two ku band SSPAs using GaAs and GaN MMICs respectively were developed. Both of all have a same 8-way combining architecture and a same packaging module. The two SSPAs were measured on a same pulse width and duty cycle with different drain voltages. Compared with the GaAs SSPA, the GaN SSPA is more compact and efficient. © (2013) Trans Tech Publications, Switzerland.


Tao Z.,Nanjing Electronic Devices Institute
IEEE Microwave and Wireless Components Letters | Year: 2015

This letter presents a broadband transition between microstrip and CPW located at the opposite lawyer of the substrate. Basically, the transition is based on two couples of microstrip-to-slotline transitions. In order to widen bandwidth of the transition, a short-ended parallel microstrip stub is added. A demonstrator transition has been designed, fabricated and measured. Results show that a frequency range of 2.05 to 9.96 GHz (referred to return loss of 10 dB) is obtained. © 2015 IEEE.

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