GaAs Preamplifier Research Articles

The ATLAS liquid argon calorimeter: upgrade plans for the HL-LHC

The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 1034 cm−2s−1. Liquid argon (LAr) sampling calorimeters are employed for electromagnetic and hadronic calorimetry. The luminosity for the proposed High Luminosity LHC phase (HL-LHC) will increase up to 5×1034 cm−2s−1 with the goal of accumulating an integrated luminosity of 3000 fb−1. This is well beyond the values for which the detectors were designed. The electromagnetic and hadronic calorimeters will be able to tolerate the increased particle flux, but the performance of the forward calorimeter (FCal) will be affected. Two possible solutions for keeping the current performance are being discussed. The readout electronics will also need to withstand larger radiation environment. In the hadronic endcap calorimeter (HEC) cold GaAs preamplifiers are located inside the endcap cryostats. The properties of these devices have been investigated in recent proton and neutron irradiation tests to determine whether they must be replaced. In addition, the entire front-end readout system is not expected to survive the integrated luminosity at the HL-LHC and will be replaced. The description of the new readout system is presented.

The ATLAS liquid argon hadronic end-cap calorimeter: construction and selected beam test results

ATLAS has chosen for its Hadronic End-Cap Calorimeter (HEC) the copper-liquid argon sampling technique with flat plate geometry and GaAs pre-amplifiers in the argon. The contruction of the calorimeter is now approaching completion. Results of production quality checks are reported and their anticipated impact on calorimeter performance discussed. Selected results, such as linearity, electron and pion energy resolution, uniformity of energy response, obtained in beam tests both of the Hadronic End-Cap Calorimeter by itself, and in the ATLAS configuration where the HEC is in combination with the Electromagnetic End-Cap Calorimeter (EMEC) are described.

System demonstration of a multigigabit network switch

4/spl times/4 single-flux-quantum (SFQ) network switch has been packaged and successfully demonstrated in a hybrid closed-cycle refrigerator (CCR) system at multigigabit data rates. Full operation of the packaged switch, with self-routing of 1-Gb/s data packets, was demonstrated using a 1-GHz address header decode. The switch is packaged on a superconducting multichip module (MCM) mounted on the 4.5-K stage of the CCR. On-chip asynchronous Josephson drivers and cooled GaAs preamplifiers are used to amplify the SFQ outputs of the switch. The maximum operation bandwidth of the switch is currently limited by the asynchronous Josephson driver. New designs of the Josephson drivers, which have demonstrated operation at 10 Gb/s, are expected to enable switch operation at 10 Gb/s. The system is equipped with fiber-optical inputs and high-speed cryogenic photodetectors. The fiber-optic interfaces, RF packaging, and MCM packaging in the CCR system have demonstrated error-free operation at 10 Gb/s.

GaAs preamplifier and LED driver for use in cryogenic and highly irradiated environments

A low-power dissipation, fast response and reasonable noise performance GaAs MESFETs preamplifier, able to work at low temperatures (89 K) and under high radiation doses, is presented. Attention is given to noise modeling for an application to particle detectors front-end electronics. Noise optimization can be achieved through careful layout design of the preamplifier's input transistor. This preamplifier is intended to be followed by a GaAs LED driver both working under the same physical conditions. A GaAs preamplifier and LED driver circuit has been designed and test results are presented and discussed in this paper.

Monolithic GaAs current-sensitive cryogenic preamplifier for calorimetry applications

We have realized low-noise monolithic GaAs preamplifiers using ion- implanted technology , to operate under low temperature and high radiation field conditions. The evaluation of noise, amplitude and timing distributions of a batch taken after first mass-production run is presented. The current-sensitive preamplifier is linear up to 8 mA of input current and able to cope a 2.2 nF detector capacitance, showing fast response ( GBW product ∼ 1.7GHz) and very low series noise. Very good noise performance at LAr temperature is obtained by using large area MESFET ( l · w = 3. 24000μm 2 ) as a head transistor, which exhibits at 8mA standing current and only 10mW power dissipation, intrinsic gain μ = g m · r ds = 15 and noise referred to the input 0.30 ÷ 0.35 H z n ¯ V According to our estimation, second stage noise contribution is negligible. Radiation damage from neutrons and γ-irradiations as well as protection network against HV discharges are discussed.

Cryogenic, monolithic, differential GaAs preamplifier for bolometric detectors

We present a first prototype of a monolithic differential voltage-sensitive preamplifier for cryogenic applications made in a GaAs ion implanted MESFET process. This preamplifier presents a very high input impedance using only a single long-tailed pair at its input, which allows the noise to be kept low. It was designed to obtain low power dissipation and a large dynamic range. The results of the first prototype chips are presented.

Radiation and cryogenic test results with a monolithic GaAs preamplifier in C-HFET technology

We report test results with a monolithic GaAs preamplifier fabricated in industrial C-HFET technology irradiated with a total dose of 10 14 neutrons/cm 2 and 100 Mrad γ radiation and operated under cryogenic conditions. The measured gate current of the input transistor of a few nA increases by < 10% after irradiation. For a 330 μm input FET width, the equivalent noise charge (ENC) is typically 145 electrons per pF total input capacitance at a shaping time of 25 ns (bipolar) before irradiation and changes approximately by 10% after irradiation. Under cryogenic operation the corresponding input referred noise decreases by roughly a factor of two.

Integration of semiconductor and ceramic superconductor devices for microwave applications

Due to the very-low-loss properties of ceramic superconductors, high-performance microwave resonators and filters can be realized. The fact that these devices may be operated at liquid nitrogen temperature facilitates integration with semiconductor devices. Examples are bandpass amplifiers, microwave-operated SQUIDs combined with GaAs preamplifiers, detectors, and MOSFET low-frequency amplifiers. The design of such circuits on a single 1-in alumina substrate using surface mount techniques is discussed. Data on circuits are presented.

Broad-band GaAs monolithic equalizing amplifiers for multigigabit-per-second optical receivers

The authors discuss the development of ICs (integrated circuits) for a preamplifier, a gain-controllable amplifier, and main amplifiers with and without a three-way divider for multigigabit-per-second optical receivers using a single-ended parallel feedback circuit, two (inductor and capacitor) peaking techniques, and advanced GaAs process technology. An optical front-end circuit consisting of a GaAs preamplifier and an InGaAs p-i-n photodiode achieves a 3-dB bandwidth of 7 GHz and -12-dBm sensitivity at 10 Gb/s. Moreover, a gain-controllable amplifier obtains a maximum gain of 15 dB, a gain dynamic range of 25 dB, and a 3-dB bandwidth of 6.1 GHz by controlling the source bias of the common-source circuit. Gain, 3-dB bandwidth, and output power of the main amplifier with the three-way divider are 17.4 dB, 5.2 GHz, and 5 dBm, respectively. These ICs can be applied to optical receivers transmitting NRZ signals in excess of 7 Gb/s.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Monolithic integration of a metal—semiconductor—metal photodiode and a GaAs preamplifier

A metal-semiconductor-metal (MSM) photodiode and a preamplifier have been monolithically integrated on a GaAs substrate by a very simple fabrication process. Measurements have shown that the constituent MSM photodiode has a sensitivity of 2.2 A/W and a -3-dB cutoff frequency of as high as 1 GHz. The present photodiode has been found to realize an extremely high photosensitivity of the monolithically integrated circuit, 26 mV/µW.

Planar monolithic integration of a photodiode and a GaAs preamplifier

A monolithic optical receiver chip consisting of a pin photodiode and a transimpedance preamplifier on a GaAs semi-insulating substrate is reported. The epitaxial layers for the photodiode are grown by hydride vapor phase epitaxy and the circuit elements are fabricated by selective ion implantation in the semi-insulating substrate. The integration scheme results in a planar surface which simplifies the processing of optoelectronic integrated chips.