dB Input Return Loss Research Articles

마이크로파용 고효율 Doherty 전력증폭기 설계

In this paper, the high efficiency Doherty power amplifier has been designed and realized for microwave applications. The Doherty amplifier has been implemented using silicon MRF 281 LDMOS FET. The RF performances cf the Doherty power amplifier (a combination of a class AB carrier amplifier and a bias-tuned class C peaking amplifier) have been compared with those of a class AB amplifier alone. The realized Doherty power amplifier P1dB output power has 33dBm at 2.3GHz frequency. Also the Doherty power amplifier shows 11dB gain and -17.8dB input return loss at 2.3GHz to 2.4GHz. The designed Doherty amplifier has been improved the average PAE by 10% higher efficiency than a class AB amplifier alone. The Maximum PAE of designed Doherty power amplifier has been 39%.

GaAs 0.5 dB NF dual-loop negative-feedback broadband low-noise amplifier IC

A GaAs dual-loop negative-feedback low-noise amplifier (LNA) designed for the square kilometre array is presented. Effects of transformer non-idealities on LNA performance are discussed. The LNA has 0.5 dB noise figure and -10 dB input return loss from 0.6 to 1.6 GHz.

Ultra-low-power 2.4 GHz image-rejection low-noise amplifier

An ultra-low-power image-rejection low-noise amplifier (IR-LNA) for 2.4 GHz ZigBee applications based on 0.18 µm CMOS technology is presented. By using the third-order active notch filter the proposed IR-LNA can achieve high image-rejection ratio. Measurements show 12 dB gain, 1.8 dB noise figure, 38 dB image-rejection, −3 dBm input third-order intercept point, −18 and −19 dB input and output return loss while dissipating 0.6 mA from a supply voltage of 1.5 V.

Feedforward 선형 전력증폭기를 위한 에러증폭기의 구현 및 성능평가에 관한 연구

In this paper. We tested and fabricated the error amplifier for the 15 Watt linear power amplifier for the IMT-2000 baseband station. The error amplifier was comprised of subtractor for detecting intermodulation distortion, variable attenuator for control amplitude, variable phase shifter for control phase, low power amplifier and high power amplifier. This component was designed on the RO4350 substrate and integrated the aluminum case with active biasing circuit. For suppression of spurious, the through capacitance was used. The characteristics of error amplifier measured up to 45 dB gain, 0.66 dB gain flatness and -15 dB input return loss. Results of application to the 15 Watt feedforward Linear Power Amplifier, the error amplifier improved with 27 dB cancellation from 34 dBc to 61 dBc IM.

An indium phosphide MMIC amplifier for 180-205 GHz

This paper describes a high-performance indium phosphide (InP) monolithic microwave integrated circuit (MMIC) amplifier, which has been developed for application in radioastronomy and imaging-array receivers. Implemented using coplanar waveguide, the six-stage amplifier exhibits 15 db gain, 10 dB input and output return loss, and low noise figure over the 180-205 GHz frequency range. Only one design pass was needed to obtain excellent agreement between the predicted and measured characteristics of the circuit, a unique achievement in this frequency band. The circuit is also the first 180-205 GHz amplifier designed for and successfully fabricated using TRW's standard 0.1-μm InP HEMT process.

Design of multistage multiway microstrip fork power dividers

The design and development of planar single-stage and double-stage 6-way and 12-way fork-type power dividers at L-band are presented. To facilitate the design using microwave CAD, wires of HP-EEsof are applied to emulate junctions formed by more than four microstrip lines. As the wiring representation of a multiway microstrip junction is not a true representation, reactive stub compensation is used in the practical development. The achieved results confirm the predicted ones, with less than +/-0.5 dB amplitude balance in insertion loss, more than 20 dB input and output return loss, and average penis' isolation more than 20 dB. (C) 1999 John Wiley & Sons, Inc.

X-band, 0.25 dB loss, high isolation MESFET switchwith goodinput and output match

The design and measured performance of a very low-loss, single pole single throw (SPST) switch operating in the C-X-band frequency range is presented. This MESFET based MMIC switch achieves 0.25 dB insertion loss, high isolation (> 25 dB) and 20 dB input and output return loss in both switch states over the 7 – 9 GHz frequency band. This design is unique in the sense that the switch maintains a very good impedance match in both the operating states without increasing the through insertion loss.

Novel multioctave MMIC active isolator (1–20 GHz)

We present a multioctave MMIC active isolator (1–20 GHz) requiring only two fidd-effect transistors (MESFETs or HEMTs) and exhibiting more than 20 dB input return loss, 18 dB output return loss with more than 20 dB reverse loss and less than 9 dB transmission loss.