J. Middleton

11 GHz bandwidth optical integrated receivers using GaAs MESFET and MSM technology

State-of-the-art performance of GaAs-FET-based monolithic optoelectronic integrated circuit (OEIC) receivers is reported. The OEIC receiver achieves -3-dB bandwidth as high as 11 GHz for optical signals at a wavelength of 850 nm. The feedback resistance of the receiver is 1000 Omega and the effective transimpedance into a 50 Omega load is 565 Omega . The effective transimpedance-bandwidth (TZBW) product is 6.1 THz- Omega . This ultra-high-performance receiver was implemented via a high-yield, low-cost direct ion implanted GaAs MESFET technology with a 0.6- mu m gate length and a metal-semiconductor-metal (MSM) detector with 2- mu m lines*3- mu m spacings.<<ETX>>

Temperature dependence study of two-dimensional electron gas effect on the noise performance of high frequency field effect transistors

We present experimental evidence that the noise figure (NF) and associated gain equal to those achieved with GaAs pseudomorphic high electron mobility transistors (GaAs p-HEMTs) can also be accomplished by ion implanted GaAs metal-semiconductor field-effect transistors (GaAs MESFETs). These measured noise figure results as a function of low temperature for GaAs MESFETs and p-HEMTs clearly suggest that the transport properties of the two-dimensional electron gas in HEMTs and p-HEMTs do not make a significant contribution to the noise reduction at high frequency operation of these devices.<<ETX>>

Low cost coplanar 77 GHz single-balanced mixer using ion-implanted GaAs Schottky diodes

A W-band single-balanced mixer and W-band LO amplifier, suitable for automotive collision-avoidance radar, have been designed and fabricated using a 0.18 /spl mu/m direct ion-implanted GaAs MESFET process developed at the University of Illinois at Urbana-Champaign. As a downconverter with an LO frequency of 77 GHz and an RF frequency of 77.1 GHz, the coplanar rat-race mixer achieves a conversion loss of 14.7 dB at an LO power of +3.5 dBm. The coplanar LO amplifier exhibits 5 dB of gain over a 4 GHz bandwidth centered at 77 GHz.

11 GHz bandwidth GaAs MESFET/MSM OEIC receivers

The authors report state-of-the-art performance of a direct ion implanted GaAs MESFET with a 0.6- mu m gate length and an MSM (metal-semiconductor-metal)-based OEIC (optoelectronic integrated circuit) receiver achieving a -3-dB bandwidth as high as 11 GHz for optical signals at a wavelength of 850 nm. The feedback resistance of the receiver is 1000 Omega , and the effective transimpedance is 565 Omega into a 50- Omega load. The effective transimpedance-bandwidth (TZBW) product is 6.1 THz- Omega for this receiver.<<ETX>>

Microwave performance of low-power ion-implanted 0.25-micron gate GaAs MESFET for low-cost MMIC's applications

Low-power microwave performance of an enhancement mode) (E-mode ion-implanted GaAs MESFET is reported. The 0.25- mu m*100- mu m E-MESFET has a threshold voltage of V/sub th/=0.0 V. At 1.0-mW operation of power with a bias condition of V/sub ds/=0.5 V and I/sub ds/-2 mA, a noise figure of 0.85 dB with an associated gain of 15 dB was measured at 4 GHz. These results demonstrate that the GaAs E-MESFET is an excellent choice for low-power personal communication applications.<<ETX>>

Optimal noise matching of 0.25 micron gate GaAs MESFETs for low power personal communications receiver circuit designs

0.25 /spl mu/m GaAs MESFETs are shown to be excellent device candidates for low current, low noise receiver circuits in personal communicators. The measured low current performance of ion-implanted 0.25 /spl mu/m gate FETs is reported for device gate widths of 100 /spl mu/m and 200 /spl mu/m and device bias conditions 0.5 V<V/sub ds/<1.5 V and 0.2 mA<I/sub ds/<5 mA. The 0.25 /spl mu/m/spl times/200 /spl mu/m device achieved a noise figure of 0.69 dB and associated gain of 12.4 dB at 2 GHz while drawing 1 mA of drain current. The matching characteristics and equivalent circuit models of these devices under low current bias conditions are also discussed.<<ETX>>

Noise performance of low power 0.25 micron gate ion implanted D-mode GaAs MESFET for wireless applications

We report on the noise performance of low power 0.25 /spl mu/m gate ion implanted D-mode GaAs MESFETs suitable for wireless personal communication applications. The 0.25 /spl mu/m/spl times/200 /spl mu/m D-mode MESFET has a f/sub t/ of 18 GHz and f/sub max/ of 33 GHz at a power level of 1 mW (power density of 5 mW/mm). The noise characteristics at 4 GHz for the D-mode MESFET are F/sub min/=0.65 dB and G/sub assoc/=13 dB at 1 mW. These results demonstrate that the GaAs D-mode MESFET is also an excellent choice for low power personal communication applications.<<ETX>>

Noise and gain comparison of 0.25 μm gate MESFETs and PHEMTs for low power wireless communication circuits

Abstract We compare the low power, low noise performance of 0.25 μm ion implanted MESFETs and epitaxially grown P HEMTs fabricated with the same geometry in order to identify the suitability of these technologies for the manufacture of hand-held personal communications products. We examine the microwave performance of the devices under low power operating conditions and we analyse the critical factors contributing to the noise performance. In the high current regime we have found that the MESFETs and P HEMTs have equivalent noise figures and gains at the bias point, which results in the lowest noise figure ( V ds = 1.5 V and I ds = 14 mA). Under low power bias, the P HEMT shows several performance advantages over the MESFET, including higher associated gain, lower R n , and lower / vbΓ opt / vb . We believe these advantages result from the sharpness of the doping profile in the epitaxial material and the rapid decrease in carrier concentration at the buried heterojunction, rather than the two-dimensional electron gas effect. Under 1 mW of d.c. bias ( V ds = 0.5 V, I ds = 2 mA) at 6 GHz, the MESFETs noise figure was 0.5 dB and its associated gain was 8 dB. The noise figure of the P HEMT for the same conditions was 0.6 dB and its associated gain was 10 dB.