Jun Fa Mao

Compact Coplanar Waveguide-Incorporated Substrate Integrated Waveguide (SIW) Filter

A novel third-order substrate integrated waveguide (SIW) filter incorporated with a coplanar waveguide (CPW) is presented in this paper. The CPW not only acts as a resonator, but also brings mixed coupling between two SIW resonators. It is shown that the filter has two transmission zeros and wide stopband, which is very compact in comparison with conventional third-order SIW counterpart. Good agreement is obtained between its measured and simulated S-parameters.

A Good Performance Design for Integrating Three Antennas in a Dual SIM Mobile Phone for GSM/DCS/Bluetooth Operations

This paper presents a dual Subscriber Identity Module (SIM) mobile phone which integrates a planar inverted-F antenna (PIFA), a monopole, and an inverted-F antenna (IFA). The main circuit board of the mobile phone has a dimension of 105 mm × 45 mm. By optimizing the multi-antenna configuration and adjusting the gap and angle of the antennas, good isolations of the three antennas are obtained. The PIFA and monopole support the Global System for Mobile communications (GSM) applications. And the measured results show that the Total Radiated Power (TRP) and Total Isotropic Sensitivity (TIS) of them satisfy the Cellular Telecommunications and Internet Association (CTIA) requirements. In addition, the IFA which enables the Bluetooth achieves a 3.79 dB gain. The presented ways are very useful for the dual SIM mobile phone design.

A dual mode filter with wideband suppression

This paper presents a novel method to suppress the harmonic responses of dual mode bandpass filters. The harmonic suppression is based on discriminating coupling. The coupling coefficient at fundamental resonant frequency can be tuned to desirable value whereas it is approaching to zero at high-order harmonic. The coupling region blocks the high-order harmonic but still allows the transmission of signals at passband frequency. Benefiting from this feature, the high order harmonic can be suppressed without degrading the passband performance. Furthermore, no additional circuit is needed. An example filter is implemented, and experimental results are presented to verify the proposed method.

Patch antenna array embedded on a high-impedance ground plane

In this paper, patch antenna array embedded on a high-impedance ground plane was studied. The metal plates of high impedance surface have same shape and almost equal dimension as patch of antenna. Due to the resonant effect, the gain of patch antenna array at = 0 increase about 4.25 dB. Especially, the first side-lobe level of antenna array was suppressed largely. Basic agreement between simulation and experiment was obtained.

A Miniaturized Semi-Lumped Lowpass Filter With Multiple Transmission Zeros And Wide Stopband

Abstract A compact semi-lumped lowpass filter with three lumped capacitors is presented in this paper. With this design, three transmission zeros can be obtained within the stopband to enhance its bandwidth. Furthermore, a transmission zero located near the passband is used to achieve sharp selectivity. A meander line between source and load is also introduced to get a compact size. Therefore, the proposed filter has a sharp skirt and wide stopband in comparison with traditional low-pass filters. A microstrip lowpass filter with lumped capacitors is designed and fabricated with the standard single-layered printed circuit board (PCB) technology. The measured S-parameters of the proposed filter agree well with the simulated ones, and the filter achieves the design performance.

An electrothermal model of interconnects based on a transmissionline network

In this paper, an electrothermal model is proposed for transient analysis of interconnects on CMOS integrated circuits excited by electrostatic discharge pulse. A thermal transmission-line network is established to model the thermal conduction in interconnect structure. The exact input impedance of the thermal network is obtained and then inverse fast Fourier transformation is used to predict transient thermal responses of interconnects. An iterative process is developed to include electrothermal effects that positive feedback occurs between the electrical and thermal behaviours of interconnects, which can impact the performance and reliability of circuits. It is shown that interconnect temperature and resistance will be underestimated if electrothermal effects and transmission line effects are ignored. Numerical results show that the proposed model is much more efficient at the cost of less than 1% error compared with thermal solver based on finite element method.

A Simplified Model of Specific Absorption Rate Calculation for Laptop-Mounted Equipment in Near Proximity to Human Torso

Abstract A simplified model of specific absorption rate (SAR) calculation is proposed for laptop-mounted equipments in proximity to human torso, in which the equivalent models of liquid phantom and laptop are investigated and studied. By improving the liquid phantom based on transmission-line theory and perfect matching layer (PML), this proposed model can improve the simulation efficiency by at least 40% while the error is within 3%. Furthermore, the effects of laptop’s geometric and electric parameters on SAR are also evaluated combined with the phantom. The accuracy and efficiency of the simplified model are validated by calculating the SAR distribution of three kinds of practical data cards and comparing SEMCAD results with the measurement ones.

Laurent_Series_Based Asymptotic Waveform Evaluation and Its Application

The novel kind of asymptotic waveform evaluation technique is presented, which is based on the Laurent series expansion instead of the traditional Taylor series expansion. Through selecting internal or external region of expansion and suitable orders of expansion, this technique can approximate functions in or out of a specific region. As an example, this technique is applied to the selection of the decoupling capacitor in the power delivery system. The results show that the proposed method can help to select the proper capacitor quickly to low the Z-profile of the system, and help to optimize the design.