Chih-Sheng Yeh

Inkjet Printed Series-Fed Two-Dipole Antenna Comprising a Balun Filter on Liquid Crystal Polymer Substrate

This paper presents a series-fed two-dipole antenna, fabricated on a liquid crystal polymer (LCP) substrate using inkjet-printing technology. The radio frequency characteristics of inkjet-printing silver film onto an LCP substrate are studied using the microstrip line. The proposed antenna consists of two modified dipole elements of distinct lengths: a modified ground plane and a balun filter yielding a wide bandwidth with bandpass responses. The proposed antenna can be used at frequency band of 26-33 GHz. The bending behaviors of the microstrip line and antenna are also measured. Inkjet printing on LCP substrates provides a low-cost, compact, and flexible packaging solution that can be used in future communication technology.

High microwave power source for 2.45 GHz wireless power charger applications

The first report on a GaN-on-Si high electron-mobility transistor (HEMT) differential oscillator is presented. A high output power and low phase noise, 2.45 GHz cross-coupled pair voltage-controlled oscillator (VCO), using 0.35 μm GaN HEMT on silicon substrate technology is described. The VCO can be tuned, between 2.41 GHz and 2.53 GHz, and has a low phase noise, of –129.09 dBc/Hz, at 1 MHz offset. The output power of the VCO is 18.31 dBm at 2.53 GHz from a 15 V power supply, while the total die size was 0.87 mm2. The high output power and low phase noise are obtained for wireless power charger applications.

Hairpin bandpass filter on Liquid Crystal Polymer substrate using inkjet printing technology

Inkjet-printing technology is utilized to fabricate a bandpass filter on a Liquid Crystal Polymer (LCP) substrates. Silver nanoparticle colloidal solution is used as the printing ink. The conductivity and thickness of silver film are 1~2×107 Siemens/m and 3.6 μm, respectively. The hairpin bandpass filter has been developed using inkjet printing technology. Bending effect causes frequency shift and insertion loss reduction due to material deformation while bending the LCP substrate.

Design of an S-band 0.35 µm AlGaN/GaN LNA using cascode topology

This paper presents an S-band low noise amplifier that uses a two-stage configuration. The first stage has a cascode topology and the second stage has a RC feedback topology. The S-band LNA uses a 0.35 μm AlGaN/GaN HEMT on a Si-substrate. The results show a maximum gain of 17.2 dB, a minimum noise figure of 2.9 dB and an input/output return loss greater than 9.2/10 dB. The input IIP3 at 2.8 GHz is 2.5 dBm and the unit consumes 230 mW of power.

A low phase noise Ka-band voltage controlled oscillator using 0.15 µm GaAs pHEMT technology

A low phase noise, low dissipated power and small sized Ka-band voltage-controlled oscillator (VCO), using dual cross-coupled pair configuration and capacitance-splitting technique is presented. The Ka-band VCO circuit uses 0.15 μm GaAs pHEMT technology. The VCO has low phase noise, of -116.36 dBc/Hz, at a 1 MHz offset and can be tuned from 30.5 to 31.22 GHz. The figure of merit (FOM) is -192.36 dBc/Hz. The power consumption of the VCO with 1.04 mm2 chip area was 24 mW, from a 1 V power supply.

A 3.5 GHz antiparallel diode pair mixer in GaN-on-Si HEMT technology

This paper presents a 3.5 GHz antiparallel diode pair mixer using a 0.35 μm GaN-on-Si HEMT technology. The antiparallel diode pair mixer has a conversion gain of -17.2 dB at 3.5 GHz. The LO-to-RF, LO-to-IF, and RF-to-IF isolation are -47.9, -34.8 and -27.5 dB at 3.5 GHz, respectively. The measured P1dB and third-order intercept point (IIP3) are +7 dBm and +17 dBm, respectively. The mixer occupies a chip area, including probing pads, of 0.9 mm2.

A Ka-band triple push coupled pair VCO using 0.18-μm CMOS technology

A low phase noise, small power dissipation and small sized Ka-band Triple Push Coupled Pair using 0.18 μm CMOS technology is described. The VCO operated can be tuned between 37.3 GHz and 40.1 GHz and has low phase noise of −107 dBc/Hz at a 1 MHz offset. The Figure of merit (FOM) is −184.8 dBc/Hz and the power-frequency tuning-normalized figure-of-merit (PFTN) is −11.8 dB. The power consumption of the VCO was 24.9 mW with only 0.52 mm2 chip area.

A 2.4/5 GHz dual-band voltage-controlled oscillator using switched resonator

A dual-band voltage-controlled oscillator (VCO) with switched resonator is described. The dual-band VCO operated near 2.4 GHz and 5.0 GHz with a phase noise of -109.4 and -100.8 dBc/Hz at a 1 MHz offset, respectively. The output powers of the VCO are 3.07 dBm at 2.56 GHz and 1.54 dBm at 5.02 GHz from a 1.0 V power supply, while the total die size was 2.12 mm2, which was achieved by using switch resonator to give good dual-band operation and performance. The power consumption was 26.8 mW for 2.4/5 GHz operations. The rf-to-dc efficiency of the 2.4 GHz and 5 GHz are 7.26% and 5.32%, respectively.