When an electric field is applied to a ferroelectric material, the microwave permittivity undergoes substantial change. This change in can be utilized devices produce frequency-agile functions. paper comprehensive review of work on materials; this includes models and loss tangent, as well methods measurement these properties. New measurements are presented thin-film strontium titanate single-crystal barium substrates. These results compared with model. A brief discussion given applications...

The load modulated balanced amplifier (LMBA) technique uses a control signal, injected at the output coupler, to modulate impedance of transistors. A 14.1-W X-band LMBA is reported, integrating for first time balanced, driver, and signal amplifiers in single microwave monolithic integrated circuit. Load modulation bias settings are used demonstrate that high circuit efficiency can be achieved as adjusted operation three RF-power regimes; 1.5, 5.6, 14.1 W constant input power 22 dBm....

This letter reports on the first demonstration of a power-combined Schottky diode frequency doubler that uses counter-rotated E-fields at output two doublers to enable in-phase H-plane power-combining. The single chip integrated circuit comprises four-anode structure 20-μm-thick GaAs substrate when used individually demonstrates peak efficiency 34% and maximum power 109 mW 180 GHz. In configuration, with exhibits 3-dB bandwidth 10% conversion 37% for input powers between 150 200 mW. delivers...

This paper extends the conventional coupling matrix theory for passive filters to design of “filter-amplifiers,” which have both filtering and amplification functionality. For this approach, extra elements are added standard represent transistor. Based on specification filter small-signal parameters transistor, active N + 3 “filter-amplifier” can be synthesized. Adopting matrix, last resonator (adjacent transistor) between them modified mathematically provide a Chebyshev response with...

Manufacture and in-service assessment of composite materials can be challenging since there is, yet, no standard method for testing them. Nevertheless, regular inspection is necessary to maintain the structural integrity. This paper describes a nondestructive, broadband noise mapping that uses millimeter-wave radiometer detect defects in materials. The W-band system configured transmission mode measurement which an amplified photonic source illuminates glass fiber reinforced polymer...

This letter presents an integrated waveguide filter amplifier using all resonator-based filtering and matching structure. An N + 4 active coupling matrix is proposed for the first time to describe topology. High-Q resonators are featured in design, achieving simultaneous at both input output ports. Easy integration of transistor with demonstrated through synthesis, where a hybrid waveguide/microstrip structure implemented structural impedance transition. In this letter, X-band device...

A novel RF power amplifier (RFPA) architecture, the orthogonal load-modulated balanced amplifier, or OLMBA, is described and demonstrated. Compared to (LMBA), OLMBA displays many of same benefits, such as active adaptive tuning using phase amplitude an external control signal, but with much lower requirements on signal (CSP). As such, a useful range can be implemented essentially no impact overall efficiency due low level signal. demonstrator measured, which delivers 30 W at minimum 50% over...

Summary form only given, as follows. The Class B to J continuum of modes, exploited here, offers levels efficiency over a impedance matching conditions, making wider bandwidth designs more feasible compared resonant harmonically tuned approaches. Circuits were designed systematically use the modes for first time at X-band. A 0.5 W MMIC fabricated using GaAs pHEMT process yields above 65% drain 30% bandwidth.

A new design methodology is presented for the planar implementation of a classical Marchand balun. novel intuitive analysis shows that configuration can be designed optimally to eliminate phenomenon “trace separation,” which frequently observed in implementations. The theory this unbalancing effect caused by parasitic transmission line formed between inner strip and ground, not considered Marchand's original coaxial structures. Compact equations are derived, based on innovative structure...

Single pole double throw (SPDT) switches are becoming more and key components in phased-array radar transmit/receive modules. An SPDT switch must be able to handle the output power of a high amplifier provide enough isolation protect low noise receive chain when T/R module is transmitting. Therefore gallium nitride technology seems become for design. The shows good performance on microwave frequencies power. X-band switch, with linear handling over 25 W, has been designed, measured...

Abstract A low loss metamaterial unit cell is presented with an integrated GaAs air-bridged Schottky diode to produce a dynamically tunable reflective phase shifter that capable of up 250° shift experimentally measured average 6.2 dB at V-band. The provides tuneable capacitance in the range between 30 and 50 fF under applied reverse voltage bias. This can be used alter resonant frequency response split patch periodic metasurface. die, which flip-chip soldered patch, has ultra-low parasitic...

This paper presents the experimental characterization of a load modulated balanced amplifier for base station applications using single input configuration. An off-the-shelf power splitter is used with coaxial cables different length to divide between branches. The effect phase offset assessed experimentally by CW tone and signal measurements, results are discussed. With proper selection cable length, achieves output 48 dBm 6 dB back-off efficiency 44 % at 1.9 GHz, while it maintains an...

Performance of a GaAs Schottky diode monolithic microwave integrated circuit (MMIC) with an waveguide backshort septum, comprising 1-2-μm-thick freestanding metal frame, is reported. The E-plane establishes short in the away from machined end wall. By defining effective using dependence multiplier performance on very high tolerance machining, this case output position, reduced. A frequency doubler design at 186 GHz exploiting approach described-with peak efficiency 40%, generates ~100 mW for...

This work presents the thermal analysis of a Schottky diode frequency doubler capable providing over 30 mW at 160 GHz room temperature. includes modeling its structure and characterization different temperature conditions. The multiplier chip layouts indicates that analyzed circuit uses optimum configuration from point view. Finally, performance predicted by physics-based numerical electro-thermal model for diodes integrated into simulator based on harmonic balance technique is also...

We present coplanar resonator measurements of the nonlinear microwave surface impedance laser ablated and electron-beam coevaporated YBa2Cu3O7−δ thin films at 8 GHz in zero applied magnetic fields, including effects irradiation with heavy ions. Correlations between changes resistance reactance as a function current suggest that there are different contributions to behavior low high currents both fields. In field, we microwave-induced flux lines responsible for observed behavior, resulting...

Measurements of the complex microwave surface impedance ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7}$ (YBCO) thin films in a coplanar resonator geometry are reported for number as function temperature and field at 8 16 GHz. Values derived dependence Labusch pinning parameter ${\ensuremath{\kappa}}_{p}$ \ensuremath{\eta}, which consistent with an independent flux-line model only weak interflux-line interactions. The observation losses mixed state scaling...

AlGaN/GaN HFETs have been analyzed using pulsed I-V measurements and RF time-domain in an attempt to analyze the phenomenon of DC-RF dispersion achieve maximum performance. The exhibited common problem current slump, as did power performance device. waveforms are used show that knee-walkout increases with drain bias voltage, thus negating any improved efficiency a larger voltage swing would achieve. It was also found degree changes depending on class operation Although slump is evident, it...

Increasingly, those who work in the field of drinking water have demonstrated an interest developing models for evolution quality from treatment plant to consumer9s tap. To date, most modelling efforts been focused on residual chlorine as a key parameter within distribution systems. This paper presents application conventional approach, first order model, and emergent artificial neural network (ANN) simulate Severn Trent Water Ltd (U.K.) system. The model depends adequate estimation decay...

Striking features have been found in the nonlinear microwave (8.0 GHz) surface impedance ${Z}_{s}{=R}_{s}+j\ensuremath{\cdot}{X}_{s}$ of high-quality YBaCuO thin films with comparable low power characteristics $[{R}_{\mathrm{res}}\ensuremath{\sim}35--60\ensuremath{\mu}\ensuremath{\Omega}$ and ${\ensuremath{\lambda}}_{L}(15\mathrm{K})\ensuremath{\sim}130--260\mathrm{nm}].$ The resistance ${R}_{s}$ is to increase, decrease, or remain independent field ${H}_{\mathrm{rf}}$ (up 60 mT) at...

This paper presents the design and thermal analysis of a high-power Schottky diode frequency doubler at 160 GHz. The is capable achieving ~10% 3 dB bandwidth with peak conversion efficiency ~25% for an input power 100 mW 295 K. Thermal characterization includes modelling measurement dissipation in discrete under different temperatures. results obtained from experiments have been validated by physics-based electro-thermal simulator diodes.

This article reports on the first Schottky diode frequency doubler with a split-block waveguide structure fabricated by high-precision stereolithography (SLA) printing process. The printed polymer parts were plated copper and thin protective layer of gold. surface roughness has been characterized critical dimensions measured, revealing good quality as well dimensional accuracy that meets tight tolerance requirements for subterahertz active devices. 62.5 to 125 GHz circuit comprises 20 μm...

This paper presents the design and performance of a x2x2 frequency multiplier chain from 40 to 160 GHz. The input power at GHz is 500 mW with final output 35 158 3 dB bandwidth over 10%. results demonstrate good agreement between modeled measured data. work described in this involved extensive thermal modelling structure including diode filter circuits; analysis allows handling for high applications.

A highly sensitive system based on a sapphire dielectric resonator has been developed to investigate the microwave properties of superconducting single crystals. The is fabricated from machined piece crystal sapphire, with hole bored along its axis accommodate samples. Samples are mounted independently heated rod, which inserted into region high field at centre resonator. Crystals can be either their c-axis or ab-planes parallel field. In former configuration predicted smallest detectable...

Increasingly, those who work in the field of drinking water have demonstrated an interest developing models for evolution quality from treatment plant to consumer's tap. To date, most modelling efforts been focused on residual chlorine as a key parameter within distribution systems. This paper presents application conventional approach, first order model, and emergent artificial neural network (ANN) simulate Severn Trent Water Ltd (U.K.) system. The model depends adequate estimation decay...

The combination of gallium nitride (GaN) device technology with the now well established efficiency enhancing Doherty power amplifier (PA) architecture is presented for first time. experimental structure exhibits a density approximately 1 W/mm and linearity that remains comparable to observed in other GaAs structures, demonstrating GaN can be highly effective when used within this type PA architecture.