SIS Mixer for 385-500 GHz with On-Chip LO injection (original) (raw)
A 550 GHz Dual Polarized Quasi-Optical SIS Mixer
1999
We describe the design, fabrication, and the performance of a low-noise dual-polarized quasi-optical superconductor insulator superconductor (SIS) mixer at 550 GHz. The mixer utilizes a novel cross- slot antenna on a hyperhemispherical substrate lens, two junction tuning circuits, niobium trilayer junctions, and an IF circuit containing a lumped element 180o hybrid. The antenna consists of an orthogonal pair of twin-slot antennas, and has four feed points, two for each polarization. Each feed point is coupled to a two-junction SIS mixer, and therefore, for each polarization there are two IF outputs and four junctions, for a total of eight junctions on the chip. Due to the mixer structure and the use of series bias of the junction pairs, it turns out that the two IF outputs for a given polarization are 180o out of phase, requiring a 180o hybrid to combine the IF outputs. The hybrid is implemented using a combination of lumped element/microstrip circuit located inside the mixer block....
A wideband fixed-tuned SIS receiver for 200-GHz operation
IEEE Transactions on Microwave Theory and Techniques, 1995
We report on the design and development of a heterodyne receiver, designed to cover the frequency range 176 GHz to 256 GHz. This receiver incorporates a niobium superconductorinsulator-superconductor (SIS) tunnel junction mixer, which, chiefly for reasons of reliability and ease of operation, is a fixed-tuned waveguide design. On-chip tuning is provided to resonate out the junction's parasitic capacitance and produce a good match to the waveguide circuit. Laboratory measurements on the first test receiver indicate that the required input bandwidth (40%) is achieved with an average receiver noise temperature of below 40 K. Mixer conversion gain is observed at some frequencies, and the lowest measured receiver noise is less than 30 K. Furthermore, the SIS mixer used in this receiver is of simple construction, is easy to assemble and is therefore a good candidate for duplication.
An SIS-based sideband-separating heterodyne mixer optimized for the 600 to 720 GHz band
Journal of Physics: Conference Series, 2008
The Atacama Large Millimeter Array (ALMA) is the largest radio astronomical enterprise ever proposed. When completed, each of its 64 constituting radio-telescopes will be able to hold 10 heterodyne receivers covering the spectroscopic windows allowed by the atmospheric transmission at the construction site, the altiplanos of the northern Chilean Andes. In contrast to the sideband-separating (2SB) receivers being developed at low frequencies, double-side-band (DSB) receivers are being developed for the highest two spectroscopic windows (bands 9 and 10). Despite of the well known advantages of 2SB mixers over their DSB counterparts, they have not been implemented at the highest-frequency bands as the involved dimensions for some of the radio frequency components are prohibitory small. However, the current state-of-the-art micromachining technology has proved that the structures necessary for this development are attainable. Here we report the design, modeling, realization, and characterization of a 2SB mixer for band 9 of ALMA (600 to 720 GHz). At the heart of the mixer, two superconductor-insulator-superconductor (SIS) junctions are used as mixing elements. The constructed instrument presents an excellent performance as shown by two important figures of merit: noise temperature of the system and side band ratio, both of them within ALMA specifications. design, modelling, realization, and characterization of a 2SB mixer for frequencies from 600 to 720 GHz corresponding to band 9 of ALMA [1]. 2. Design and Modelling From a variety of possible 2SB schemes, we have selected the configuration shown in figure 1. The RF to be detected is brought to a hybrid which separates the signal into two branches of equal amplitude but with a phase separation of 90°. Each branch is coupled with the LO signal and mixed into two non-linear devices (SIS junctions in this case). The resulting IF signals are brought to a new 90° hybrid after which two new IF signals are obtained corresponding to USB and LSB, respectively. We have opted for waveguide technology for the construction of the RF components and planar stripline for the IF filtering and matching parts. Each one the RF components and the planar IF system were modeled independently using commercial microwave-analysis software (Microwave Studio *). The dimensions of every RF component were selected for an optimal performance in the 600−720 GHz range. On the other hand, the IF signal is intended to cover 4−8 GHz.
International Journal of Infrared and Millimeter Waves, 1994
A heterodyne receiver using an SIS waveguide mixer with two mechanical tuners has been characterized from 480 GHz to 650 GHz. The mixer uses either a single 0.5 x 0.5 I.tm 2 Nb/AIOx/Nb SIS tunnel junction or a series array of two 1 I.tm 2 Nb tunnel junctions. These junctions have a high current density, in the range 8-13 kA/cm 2. Superconductive RF circuits are employed to tune the junction capacitance. DSB receiver noise temperatures as low as 200 + 17 K at 540 GHz, 271 K+_22 K at 572 GHz and 362+ 33 K at 626 GHz have been obtained with the single SIS junctions. The series arrays gave DSB receiver noise temperatures as low as 328 + 26 K at 490 GHz and 336 + 25 K at 545 GHz. A comparison of the performances of series arrays and single junctions is presented. In addition, negative differential resistance has been observed in the DC I-V curve near 490, 545 and 570 GHz. Correlations between the frequencies for minimum noise temperature, negative differential resistance, and tuning circuit resonances are found. A detailed model to calculate the properties of the tuning circuits is discussed, and the junction capacitance as well as the London penetration depth of niobium are determined by fitting the model to the measured circuit resonances.
A 0.5 THz Sideband Separation SIS Mixer for APEX Telescope
We present the design and the experimental results of a fixed-tuned sideband-separating superconductor-insulatorsuperconductor (SIS) mixer for 385 -500 GHz. The sideband separation is achieved using a quadrature scheme, where two separate DSB mixer blocks are combined with an intermediate waveguide component containing the LO waveguide distribution circuitry and RF waveguide hybrid. The intermediate waveguide piece is fabricated by using copper micromachining, which gives dimensions' accuracy better than 1 μm. The RF signal
A dual-polarized quasi-optical SIS mixer at 550 GHz
IEEE Transactions on Microwave Theory and Techniques, 2000
We describe the design, fabrication, and the performance of a low-noise dual-polarized quasi-optical superconductor insulator superconductor (SIS) mixer at 550 GHz. The mixer utilizes a novel cross-slot antenna on a hyperhemispherical substrate lens, two junction tuning circuits, niobium trilayer junctions, and an IF circuit containing a lumped element 180 • hybrid. The antenna consists of an orthogonal pair of twin-slot antennas, and has four feed points, two for each polarization. Each feed point is coupled to a two-junction SIS mixer. The 180 • IF hybrid is implemented using a lumped element/microstrip circuit located inside the mixer block. Fourier transform spectrometer (FTS) measurements of the mixer frequency response show good agreement with computer simulations. The measured co-polarized and cross-polarized patterns for both polarizations also agree with the theoretical predictions. The noise performance of the dual-polarized mixer is excellent, giving uncorrected receiver noise temperature of better than 115 K (DSB) at 528 GHz for both the polarizations.
A 350GHz SIS antipodal finline mixer
IEEE Transactions on Microwave Theory and Techniques, 2000
In this paper, we describe the design and operation of a 350-GHz finline superconductor-insulator-superconductor mixer. The mixer is fed by a horn-reflector antenna, and the superconducting circuit is fabricated using planar-circuit technology and fully integrated tuning. An important feature of the mixer is that it employs an antipodal finline section, deposited on one side of a quartz substrate, which transforms the high impedance of the waveguide ( 300 ) to the low impedance of the microstrip ( 20 ). The Nb/Al-oxide/Nb tunnel junction is fabricated at the same time as the finline circuit. In this paper, we describe the design procedure in some detail. We pay particular attention to the synthesis of the finline taper and the electromagnetic design of the horn-reflector antenna. We have tested a finline mixer over the frequency range of 330-370 GHz and measured a receiver noise temperature of 90 K, which remained unchanged over the whole frequency range. Our investigation has demonstrated that it is possible to make superconducting finline mixers for frequencies as high as 350 GHz.
A 275–425-GHz Tunerless Waveguide Receiver Based on AlN-Barrier SIS Technology
IEEE Transactions on Microwave Theory and Techniques, 2007
We report on a 275-425-GHz tunerless waveguide receiver with a 3.5-8-GHz IF. As the mixing element, we employ a high-current-density Nb-AlN-Nb superconducting-insulatingsuperconducting (SIS) tunnel junction. Thanks to the combined use of AlN-barrier SIS technology and a broad bandwidth waveguide to thin-film microstrip transition, we are able to achieve an unprecedented 43% instantaneous bandwidth, limited by the receiver's corrugated feedhorn. The measured double-sideband (DSB) receiver noise temperature, uncorrected for optics loss, ranges from 55 K at 275 GHz, 48 K at 345 GHz, to 72 K at 425 GHz. In this frequency range, the mixer has a DSB conversion loss of 2.3 1 dB. The intrinsic mixer noise is found to vary between 17-19 K, of which 9 K is attributed to shot noise associated with leakage current below the gap. To improve reliability, the IF circuit and bias injection are entirely planar by design. The instrument was successfully installed at the Caltech Submillimeter Observatory (CSO),
Development of 460 GHz and Dual Polarization SIS Mixers for the Submillimeter Array
IEEE Transactions on Applied Superconductivity, 2011
A heterodyne receiver incorporating superconductorinsulator-superconductor (SIS) mixers has been designed to cover the frequency range from 400 to 520 GHz of the Submillimeter Array (SMA). Various tuning circuits have been employed to resonate out the geometric capacitance of the junction and provide impedance matching to the waveguide probe. Our measurements indicated that a receiver noise temperature of around 90 K, with the contributions from the input noise and intermediate frequency (IF) noise estimated to be around 60 K and 10 K, respectively. SIS mixers integrated with planar orthomode transducers (OMT) have also been designed at 345 GHz for dual polarization detections, and results from the 3-dimensional (3-D) electromagnetic (EM) simulations are presented.