Microwave Receiver Research Articles

A Compact Photonic Microwave Receiver Integrated with Dielectric Resonator Antenna

A novel structure for antenna-integrated photonic microwave receiver is proposed. The volume of the photonic microwave receiver can be greatly reduced by directly coupling a dielectric resonator antenna to the microdisk-based modulator. Simulation results show good performance for this structure.

Self‐homodyne photonic microwave receiver architecture based on linear optical modulation and filtering

AbstractWe present a self‐homodyne photonic microwave receiver architecture that uses linear optical modulation and optical filtering for data down‐conversion from a microwave carrier. Preliminary results demonstrate the feasibility of this technique for demodulating up to 100 Mb/s digital data from carrier frequencies above 10 GHz. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 345–350, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23065

Theodore Harold Maiman

Theodore Harold Maiman

In the service of national security

The use of whispering-gallery-mode optical resonators has enabled the creation of a microwave receiver that is immune to electromagnetic attack.

A Miniaturized Spectrometer Radiometer Based on MMIC Technology for Tropospheric Water Vapor Profiling

The fabrication of a miniaturized ground-based water vapor profiling radiometer demonstrates the capability of monolithic microwave and millimeter-wave integrated circuit technology to reduce the mass and volume of microwave remote sensing instrumentation and to reduce substantially the necessary operational power consumption and size of the radio-frequency and intermediate-frequency sections. Since those sections comprise much of the mass and volume of current microwave receivers, the fabrication of this system represents an important contribution to the design of microwave radiometers. This miniaturized radiometer implementation is particularly well suited to benefit from the cost savings associated with mass production. The small size of the radiometer (24times18times16 cm) reduces the power required by the temperature control system and allows a rapid warm-up to the temperature set point as well as maintenance of a highly stable internal temperature. Exhibiting very similar statistical properties, the four channels of the radiometer have measured Allan times of greater than 40 s. Measurement results demonstrate that the instrument achieves a sensitivity of better than 0.2 K for 3 s of integration time. Preliminary comparisons of measured brightness temperatures with simulation results based on radiosonde data show good agreement, which are consistent with previously reported results.

Direct-write trilayer technology for Al–Al2O3–Cu superconductor-insulator-normal metal tunnel junction fabrication

The authors present a novel direct-write trilayer technology for bolometer and thermometry applications. The technology is based on in situ evaporation of the superconductive electrode followed by the oxidation and the normal counterelectrode as a first step and deposition of normal-metal absorber as a second one. This approach allows one to realize any geometry of the tunnel junctions and of the absorber with no limitation related to the size of the junctions or the absorber, which is not possible using shadow evaporation technique. The proposed new approach is perfectly suited for fabrication of microwave receivers for high-precision measurements in new generation of telescopes such as CLOVER ground-based telescope and OLIMPO balloon telescope projects. Measurements performed at 300mK showed high quality of fabricated tunnel junctions, low leakage currents, and Rd∕Rn ratio of 500 has been achieved at that temperature. The junctions were characterized as temperature sensors, and voltage versus temperature dependence measurements have shown a dV∕dT of 0.5mV∕K for each single junction, which is typical for this kind of tunnel junctions.

Simultaneous Electromagnetic Measurement Using a Parallel Modulated Probe Array

A simultaneous measurement method using a parallel modulated probe array is proposed to measure the electromagnetic field radiated by antennas at different locations simultaneously. Each modulated probe is excited by a local signal with different frequency, so that the received intermediate frequency (IF) signal contains different frequency components which indicate the relative magnitude of the radio-frequency signal at positions of the probes, and all the IF components are measured simultaneously by a broadband microwave receiver. The effect of the local signal on the received IF signal and interaction effect between the probe array and the measured antenna are investigated. The accuracy of the method is shown by measuring the antenna radiation pattern. A 3D antenna radiation measurement system based on the present method is also developed. The performance of the system is demonstrated by measuring the radiation efficiency of antennas.

Experimental Verification of Phase Retrieval of Quasi-Optical Millimeter-Wave Beams

The accuracy of a phase-retrieval procedure for microwave beams was analyzed and verified using an 84-GHz quasi-optical beam transmitted by a corrugated waveguide. The output intensity and phase profiles of the beam were directly measured with a microwave receiver. The beam intensity was also measured at several planes and the data were used with a phase-retrieval algorithm to yield an independent estimate of the phase. Moment and matching coefficient methods were used to analyze the retrieved profiles. In the higher order moment analysis, the intensity profiles, which were calculated from the retrieved phase profiles, coincided well with the measured profiles in terms of the beam size, asymmetric property (skewness), and flatness/peakedness (kurtosis) over the entire profile. Analysis indicated that the mode content of the beam obtained by phase retrieval matched that of the direct measurement with a matching coefficient of 0.97 using both the intensity and phase profiles

Microwaves in fire detection

In this contribution the issue of fire detection by means of thermal radiation in the microwave region of the electromagnetic spectrum is addressed. The aim of this work is to show that microwave radiation is a useful quantity to detect fires, which is confirmed by measurements. Some of the results even indicate that it could be possible to detect smoldering fires with microwaves earlier than with smoke or with gas detectors. The first part is a short summary of the basic concept of our previous paper [Kaiser T, Kempka T. Is microwave radiation useful for fire detection? Proceedings of 12th international conference on automatic fire detection AUBE ’01, vol. 965, 26–28 March 2001. Gaithersburg: NIST Special Publication; 2001.] published at AUBE ‘01, along with a short revisit of the physical fundamentals of thermal radiation, of electromagnetic wave propagation, and of attenuation. In the second part, the microwave receiver will be presented, which is used to conduct experiments in Duisburg's fire detection lab. The receiver is able to measure thermal radiation in the frequency region from 2 to 40 GHz, and the superheterodyne technique used by the receiver enables a rather flexible measurement range among arbitrary frequency bands with individual widths of 100 MHz. The receiver is controlled by a normal PC, which makes the measurement setup configurable, i.e. one can choose any combination of 380 × 100 MHz frequency bands for a single measurement. Some measurement results for the standardized European test fires TF1 and TF2 according to ISO 7240 (EN 54 Part 9) are shown in the last part of this contribution. The gathered data is discussed and compared to ionization chamber (MIC), to extinction light sensor (MIREX), and to gas-concentration measurements.

Knots detection in wood using microwaves

This work describes a microwave technique used to generate and process data on knots in wood prior to processing. The experimental design was a simple system composed of a microwave emitter and receiver used to scan the wood samples with knots. Signals were calibrated and amplified, and then a data storage and graphic visualization were performed. A PCL-711 data acquisition card was used in conjunction with data acquisition software. The preliminary results obtained for the studied wood samples were viewed in 2- and 3-dimensional graphics, showing a strong relation with the visual inspection of the samples.

The RED Experiment: An Assessment of Boundary Layer Effects in a Trade Winds Regime on Microwave and Infrared Propagation over the Sea

The Rough Evaporation Duct (RED) experiment was performed off of the Hawaiian Island of Oahu from late August to mid-September 2001 to test the hypothesis that a rough sea surface modifies the evaporation duct. Two land sites were instrumented, one with microwave receivers and the other with an infrared receiver. Two bouys were deployed, a small boat was instrumented and two aircrafts flew various tracks to sense both sea and atmospheric conditions. It was observed that waves do modify the scalars within the air-sea surface layer. There was a lack of agreement of the scalar profile constants and those typically observed over land. Furthermore, evidence was obtained indicating that the Monin-Obukhov similarity theory, combined with high-quality meteorological measurements, can be used by propagation models to accurately predict microwave signal levels.

Summary of studies on space solar power systems of the National Space Development Agency of Japan

National Space Development Agency of Japan has examined studies on Space Solar Power Systems (SSPS) since FY1998 organizing a special committee and working group. The FY 1998 studies focused on creating a life cycle cost model of the SSPS which sends energy to the Earth using microwave beams (Microwave Power Transmission; MPT). With the use of this model, technological sensitivity was analyzed to identify key research issues that must be pursued in the future. In addition, a conceptual study was conducted on the SSPS using laser power transmission, with attention paid to fiber array lasers. The FY1999 studies examined a system concept of SSPS, and three types of configurations were proposed. We also proposed a draft of the engineering demonstration satellite while examining major element technology. The FY2000 studies surveyed maturity of major element technologies to exam SSPS system concept. Computer simulation of a direct solar pumping solid-state laser, 5.8 GHz microwave transmitter and receiver system and “sandwich module” integrated PV cell, microwave transmitter and antennas were examined as demonstration of element technology.

Design of HTS coplanar waveguide matching circuit for low noise CMOS-HTS receiver

For realizing a single chip HTS integrated microwave receiver, a superconducting slot antenna and a Si-CMOS low noise amplifier (LNA) combined with a broad band matching circuit composed of coplanar waveguide (CPW) meanderline resonators has been designed and tested. By applying the filter technique and using admittance inverters (J inverters), we propose a new design method of CPW broadband impedance matching circuit connected to low and high impedance loads such as HTS antenna and CMOS device. Based on the design method, we designed a Chebyshev type impedance matching circuit connecting with slot antenna and CMOS-LNA at 10 GHz center frequency. More over, in order to increase the antenna directivity, we designed 2-dimensional antenna array by folding the slot antenna.

Analysis of the tuning and operation of reflection resonator EPR spectrometers

This paper investigates basic characteristics of the electron paramagnetic resonance (EPR) signal obtained from spectrometers employing reflection resonators. General equations are presented which reveal the phase and amplitude dependence on instrumental parameters of both components of the continuous wave (CW) EPR signal (absorption and dispersion). New phase vector diagrams derived from these general equations are presented for the analysis of the EPR response. The dependence of the phase and absolute value of the CW EPR signal on the local oscillator (LO) phase and on resonator offset and coupling is presented and analyzed. The EPR spectrometer tuning procedures for both balanced and unbalanced heterodyne receivers are analyzed in detail using the new phase diagrams. Extraneous signals at the RF input of the microwave receiver (resulting from circulator leakage and reflections in the resonator transmission line) have been taken into account and analyzed. It is shown that a final tuning condition that corresponds to an extremum of the receiver output as a function of the resonator frequency is necessary and sufficient for the acquisition of pure absorption signal. This condition is universal: it applies to all spectrometer configurations in all frequency ranges. High Frequency EPR spectrometer (130 GHz) data are used to generate experimental phase diagrams that illustrate the theoretical concepts presented in the paper. Conditions are presented under which the absorption signal can be measured with complete suppression of the dispersion, independent of the mutual frequency offset between the microwave source and the EPR sample resonator. Equations describing the approximate relationship between changes of the resonator properties ( Q-factor and frequency) and paramagnetic susceptibility are derived and analyzed.

Surface resistance measurement of superconducting thin film using probe‐coupling‐type microstrip line resonator

AbstractTo design superconducting microwave receivers, the surface resistance of the superconducting thin film must be considered. Therefore, a highly accurate technique for measuring the surface resistance of superconducting thin films should be established. In this paper, we propose a probe‐coupled microstrip line resonator as a technique for measuring the surface resistance of superconducting thin films. In the resonator technique, the surface resistance is calculated from Qu, the unloaded Q, of the resonator. Since the microstrip line resonator searches for an accurate surface resistance of the superconducting thin film, establishing a technique that accurately determines the Qu of the resonator is crucial. We measure the Qu values of resonators fabricated from metal and superconducting thin film by a probe‐coupled microstrip line resonator and describe the accuracy of Qu measurement by the probe‐coupled micro‐strip line resonator and the repeatability of the surface resistance measurement of a superconducting thin film. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(4): 27–35, 2003; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/ecjb.10035

Whispering-gallery-mode electro-optic modulator and photonic microwave receiver

We report on the experimental observation of efficient all-resonant three-wave mixing using high-Q whispering-gallery modes. The modes were excited in a millimeter size toroidal cavity fabricated from LiNbO3. We implemented a low-noise resonant electro-optic modulator based on this wave mixing process. We observe an efficient modulation of light with coherent microwave pumping at 9 GHz with applied power of approximately 10 mW. Used as a receiver, the modulator allows us to detect nanowatt microwave radiation. Preliminary results with a 33-GHz modulator prototype are also reported. We present a theoretical interpretation of the experimental results and discuss possible applications of the device.

The MAP Satellite Feed Horns

We present the design, manufacturing methods, and characterization of 20 microwave feed horns currently in use on the Microwave Anisotropy Probe (MAP) satellite. The nature of the cosmic microwave background (CMB) anisotropy requires a detailed understanding of the properties of every optical component of a microwave telescope. In particular, the properties of the feeds must be known so that the forward gain and sidelobe response of the telescope can be modeled and so that potential systematic effects may be computed. MAP requires low emissivity, azimuthally symmetric, low-sidelobe feeds in five microwave bands (K, Ka, Q, V, and W) that fit within a constrained geometry. The beam pattern of each feed is modeled and compared with measurements; the agreement is generally excellent to the -60 dB level (80 degrees from the beam peak). This agreement verifies the beam-predicting software and the manufacturing process. The feeds also affect the properties and modeling of the microwave receivers. To this end, we show that the reflection from the feeds is less than -25 dB over most of each band and that their emissivity is acceptable. The feeds meet their multiple requirements.

Sub-microwatt photonic microwave receiver

We report efficient photonic reception of nanowatt microwave signals by their direct upconversion into optical domain using high-Q whispering gallery modes in a millimeter size toroidal cavity fabricated from LiNbO/sub 3/.

50 years development of the microwave mixer for heterodyne reception

A brief technical historical review of mixer development, in its application as the frequency down-converter for the microwave and millimeter-wave heterodyne receiver, provides the background to discussion of mixer design, technology, and performance characteristics. In general terms, today's mixers designs are based on the 1970s principles, but technology progress in the solid-state frequency-mixing element and associated integrated circuits has been significant, with exploitation of the monolithic potential. Performance advancements have mainly been in the increased frequency capabilities of the planar Schottky barrier diode mixer, broad application of the three terminal devices, and balun implementation.

Digital microwave receiver technology

This paper reports the impact of digital signal processing on microwave receiver technology. The majority of modern receiver designs are based on digital technology. Wide-and narrow-band receivers are presented. The wide-band receivers cover approximately 1-GHz instantaneous bandwidth and are used to intercept radar pulses. Current narrow-band receivers cover up to 50-MHz instantaneous bandwidth and are primarily used for receiving communication signals. Two approaches for wide-band receiver design are discussed. One is the conventional digital receiver. The other one is called the monobit receiver, which has slightly inferior performance in some respects, but can be built on a single chip. Narrow-band receivers are best implemented in software because they can more adapt to changes. Two types of receivers are discussed. One is the software Global Positioning System receiver. The other one is called a transform-domain communication system. The object of this system is to avoid interference in a hostile communication environment.