Cryogenic, X-band and Ka-band InP HEMT based LNAs for the Deep Space Network

Abstract

Exploration of the Solar System with automated spacecraft that are more than ten astronomical units fiom earth requires very large antennae employing extremely sensitive receivers.A key figure of merit in the specification of the spacecraft-to-earth telecommunications link is the ratio of the antenna gain to operational noise temperature (G/Top) of the system. The Deep Space Network (DSN) receivers are cryogenic, low-noise amplifiers (LNAs) which address the need to maintain Top as low as technology permits.Historically, the extra-ordinarily sensitive receive systems operated by the DSN have employed cryogenically cooled, ruby masers as the LNA. Recent advances in the development of indium phosphide (InP) based high electron mobility transistors (HEMTs) combined with cryogenic cooling have made this technology competitive with standard DSN maser technology. InP HEMT LNA modules are demonstrating noise temperatures less than ten times the quantum noise limit (10hfk) from 1 to 100 GHz. To date, the lowest noise LNA modules developed for the DSN have demonstrated noise temperatures of under 4 K at 8.4 GHz and 11 K at 32 GHz. Front-end receiver packages employing these modules demonstrated operating system noise temperatures of 17 K at 8.4 GHz (on a 70m antenna at zenith) and 39.4 K at 32 GHz (on a 34m antenna at zenith).The development and demonstration of cryogenic, InP HEMT based front-end amplifiers for the DSN requires accurate component and module characterization, and modeling from 1 to 100 GHz at physical temperatures down to and below 12 K, because of the broad band frequency response of InP HEMTs.The characterization and modeling begins with the HEMT chip, proceeds to the multi-stage HEMT LNA module, and culminates with the complete front-end cryogenic receiver package for the antenna.This paper presents an overview of this development process with emphasis on comparison between modeled and measured results at 8.4 GHz. Results will be shown for devices, LNA modules, front-end receiver packages employing these modules, and antennae employing these packages.

Very low-noise differential radiometer at 30 GHz for the PLANCK LFI

“…The LNA gain was approximately 34.7 dB and pairs of LNAs were matched in gain and phase. The average noise temperature over the 6-GHz bandwidth was 9.4 K at 15 K. These results are among the best reported [15], [16]. The gain in decibels and the noise temperature in kelvin over the operating bandwidth of one LNA is depicted in Fig.…”

“…The hot and cold waveguide termination temperatures ( , , and ) that appear in Table II were used. This method is based on power measurements through the -factors, as in (14) and (15). System equivalent noise temperature and leakage versus frequency are depicted in Fig.…”

Cryogenic wide-band ultra-low-noise if amplifiers operating at ultra-low DC power

“…I nP-BASED high electron-mobility transistors (HEMTs) offer state-of-the-art low-noise performance and superior high-frequency performance [1]- [5]. The high mobility and carrier velocity in the InGaAs layer result in excellent performance at very low drain-to-source voltages.…”

Cryogenic dual‐temperature low noise amplifier in K band

“…The most critical passive part is the transition from the input waveguide WR42 (10.67 × 4.32 mm 2 ) to the microstrip line where the monolithic microwave integrated circuit (MMIC) LNA is soldered. This transition is intended to have an insertion loss as low as possible over the entire frequency range (18)(19)(20)(21)(22) and over the entire temperature range (300-103 K) while presenting compact dimensions. In fact, since the entire LNA is cooled down to cryogenic temperatures, it is fundamental to minimise the overall mass and volume in order to achieve a rapid transition between room and cryogenic temperature.…”

“…4 Measured port matching of the passive mock-up at 300 K room temperature (300 K) from 1.8 to 2. This was selected to minimise the risk for the prototype development and a better NF can be obtained with InP HEMT (mHEMT or pHEMT), if required [18].…”