HEMT Preamplifier Research Articles

Erratum to: Electrons in a cryogenic planar Penning trap and experimental challenges for quantum processing

The energy dissipated in HEMT preamplifier is permanently coupled to the the trapped electrons and causes an axial temperature of about 5K. In the experiment [1] (cited as [13] in original article) electronic feedback allows cooling from 5.2 K down to 0.85 K. The trapping potential anharmonicity is a feature for the planar traps, though could be very useful feature for 3D cylindrical Penning traps [1,2] ([13,18] in original article). In experiments [3,4] the fourth-order nonlinearity established parametric excitations of the electron cloud near its axial resonance frequency, while the power of the parametric pump exceeds threshold value electrons synchronize their motion and were used for the probing of modes structure of the trap cavity. A further development of this technique [5] used a single electron parametric oscillator as one-bit memory to measure cyclotron excitation thus allowing to perform all measurements “in the dark” insofar all axial drives and preamplifier are turned off to avoid significant increase of the axial temperature. We apologize that not all necessary articles were cited in our article.

Nonequilibrium response of a meandered MgB 2 sensor by the irradiation of a pulsed laser

We studied the thermal response of superconducting MgB 2 detectors by irradiating 20-ps pulsed laser. We produced a 1-μm or 3-μm line and space meandered line of MgB 2 film on a sapphire substrate. We used a low-noise HEMT preamplifier at 23 K or a low-noise preamplifier at room temperature to recover tiny signals. Systematic studies of the transient signals with various bias currents and temperatures are reported to optimize measurement conditions. The maximum operating speed of our MgB 2 detector was found to be 1.3 ns when the fast electronics was used. Our MgB 2 detector can be used as a neutron detector by using nuclear reaction between neutron and 10B in MgB 2.

European Minor Constituent Radiometer: A New Millimeter Wave Receiver for Atmospheric Research

EMCOR is a heterodyne receiver for the frequency range of 201 to 210 GHz. It has been designed for ground-based measurements of various minor constituents of the stratosphere involved in ozone chemistry. Since the aim was the detection of faint spectral lines, a superconducting tunnel junction has been chosen as mixer element and special care has been taken in developing the calibration unit of the system. The front-end is completed by a quasi-optical system, a solid state local oscillator with electronic tuning and a HEMT pre-amplifier. In the back-end an acousto-optical spectrometer is employed to analyse the signal. A PC controls the whole system. The instrument has been installed at a high mountain site in the Swiss Alps.

Sensitivity analysis of integrated InGaAs MSM-PD's and HEMT optoelectronic receiver array

A sensitivity analysis is given of a long wavelength optoelectronic receiver array consisting of InAlAs/InGaAs interdigitated Metal Semiconductor Metal photodetectors (MSM-PD's) and a HEMT preamplifier. It is shown that the capacitance varies with the finger width and spacing for a MSM-PD with same active area. Analytical expressions are derived for calculating the sensitivity of the receiver array by means of the equivalent circuit models of the MSM-PD's array and the HEMT. Major noise sources in the receiver array, such as shot noise in the photodetectors, thermal noise in the resistors, gate and drain noises as well as their correlation term in the HEMT, are considered. The influences of geometric parameters of the MSM-PD's and HEMT on the sensitivity of the receiver array are investigated. The optimum gate width of the HEMT is determined for a given MSM-PD array to obtain a high receiver sensitivity. It is also demonstrated that the optical signal related shot noise from the MSM-PD's makes a substantial contribution to the total noise of the receiver array.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

High-performance Al0.48In0.52As/Ga0.47In0.53As MSM-HEMT receiver OEIC grown by MOCVD on patterned InP substrates

We report the first demonstration of a new long-wavelength receiver OEIC comprising an AlInAs/GaInAs MSM detector and an AlInAs/GalnAs HEMT preamplifier. The layer structure was grown by LP-MOCVD on patterned InP substrates, which allowed independent optimisation of the MSM detector and HEMT preamplifier. The MSM detector showed the lowest leakage current yet reported and the HEMT exhibited a transconductance of 260mS/mm. An excellent receiver response to l.7Gbit/s NRZ signals has been obtained.

20 GHz bandwidth low-noise HEMT preamplifier for optical receivers

A broadband, low-noise HEMT preamplifier is designed for very high-speed fibre-optic transmission systems. A 20 GHz 3dB down bandwidth and 7.6pA/√(Hz) averaged input equivalent noise current density from 100 MHz to 18 GHz are achieved using inductor peaking techniques and low stray capacitance chip resistors.