Jiun-Yu Wen

Chip design of an 8 MHz CMOS switched-capacitor low-pass filter for signal receiver applications

In this paper, a fifth-order elliptical low-pass filter using switched-capacitor (SC) architecture is proposed. The filter has a pass-band of 8 MHz and clock frequency of 80 MHz. The proposed filter is realized by cascades of first-order and second-order biquad building blocks. In order to reach the largest possible input dynamic range and save chip area, the method of dynamic range scaling and minimum capacitor scaling is used. Measurement results show that the proposed SC low-pass filter achieves a pass-band frequency of 8.72 MHz. The chip area including pads is 0.895 mm2 and the power dissipation is 44.2 mW at the supply voltage 1.8 V.

Design of a compact planar UWB filter for wireless communication applications

An ultra-wideband (UWB) bandpass filter (BPF) for wireless communications is proposed in this paper. The BPF contains a stepped impedance resonator (SIR) and an improved split-ring resonator defected ground structure (SRR DGS). Both measurement and simulation are very matched and indicate that the proposed BPF achieves good characteristics with flat insertion loss less than 1 dB, and good return loss less than −15 dB respectively over the whole band of 3.1 to 10.6 GHz, attenuation higher than 20 dB and 15 dB to the lower stopband and the upper stopband, respectively. It only occupies a small area of 10×15 mm2 and consumes no power.

Design of Broadband Planar Inverted F Antenna Using the Resonant Frequency to the next Reactance Equal to Zero

In this paper, we propose a novel design of broadband and easy fabrication F antenna for ISM band. The antenna structure is flexible and capable of being realized in various application cases. Reduced short circuit plate (RSC), and low resonant frequency (LRF) for PIFA design are applied to design a compact F antenna with the aid of a 2.5D field simulator, IE3D. Not only does RSC give better impedance matching, but the LRF provides broader bandwidth. Both designed PIFAs are operated at wireless LAN of IEEE 802.11b,g. Measurements indicate that the LRF achieves -10dB bandwidth up to 304 MHz(12.4%) ranging from 2.332 GHz to 2.636 GHz, and the peak gain is 3 dBi. The RSC has a bandwidth up to 220MHz (9%) ranging from 2.36 GHz to 2.58 GHz, and the gain is 2.5 dBi. Actually, our design F antennas reach broadband, miniaturization, lower return loss, and easy to fabricate.

Chip Design of an UWB, High Gain and Low Noise Amplifier for Wireless Applications

An ultra-wideband (UWB), high gain and low-noise amplifier (LNA) for wireless applications is presented in this paper. Operating at the frequency band of 0.8-6.0 GHz and fabricated in TSMC 0.18-um technology, the measured results show the gain of 17-19 dB, the noise figure (NF) less than 4.8 dB, the input third-order intercept point (IIP3) of -17 dBm, the reverse isolation less than -25 dB and the power dissipation of 43.2 mW at 1.8 V voltage supply. The chip area including pads is only 1.027mm2.

Planar Coupled UWB Dipole Antenna with Notched Function to Prevent ISM Band from Interference

An UWB dipole antenna comprising of an arbitrary notched band function to prevent ISM band from interference is presented. The proposed dipole antenna demonstrates the UWB operation with an adjustable notched band and is designed on a commercial substrate FR4 having a thickness of 1.6 mm and 4.4 permittivity. Experimental results verify that the proposed antenna achieves a bandwidth covering from 3.1 to 10.6 GHz with VSWR below 2 including the WLAN band notched at the vicinity of 5 GHz, such as the 5.2 GHz band (5150–5350 MHz) and 5.8 GHz band (5725–5875 MHz). The band gain is about 4 dB and sharply decreases about 8 dB to -4 dB for the notched band. This design method offers impressive gain characteristics and can be applied to other frequency bands of interest.

Investigation of Electromagnetic Radiation from High Power Weather Radar

In this paper, we devote to investigate the electromagnetic (EM) radiation characteristics and radiation intensity of high power weather radar once extensively. We compare our field measurement with international specifications and an operating early-warning radar case study also made a contribution to those who are interested in the healthy effect of high power EM radiation. The measured data is much lower than the recommended specifications announced by EPA and ICNIRP. It shows that no direct evidence can prove that radiation may cause harms to human beings. Keywords--weather radar, high power radiation, electromagnetic radiation.

Chip design of phase-locked loop for ISM band applications

A TSMC 0.35um CMOS 2P4M process PLL (phase-locked loop) for ISM band applications is proposed. The PLL, with a crossed-coupled pMOS ring-oscillator VCO, is realized without using any inductor. Measurement results show that at the supply voltage of 3.3 V and the lowest reference frequency of 25 MHz, the locking range is from 1.8 GHz to 3.29 GHz, locking time is less than 3 us and the phase noise is −107.1 dBc/Hz at 1 MHz offset. The total power consumption of the PLL is 85.4 mW at center frequency of 2.48 GHz. The core chip area is only 0.17 mm2 and including pad, it is 1.02 mm2.