A broadband millimetre-wave passive spatial combiner using a microstrip probe array and an oversized coaxial waveguide is successfully designed and tested. The equivalent circuit approach of transverse electromagnetic (TEM) lines is adopted to synthesise the coaxial stepped impedance transformer from a K connector with the oversized coaxial waveguide and to analyse the microstrip probe array. T...

Abstract—An X-band active radial-waveguide pulsed power amplifier (PA) with high power and high power added efficiency (PAE) is designed, fabricated, and measured in this paper. A bandwidth of 1000 MHz with peak power level of 53.2 dBm at the frequency 9.85GHz, under the condition of 4 kHz pulse repeat frequency (PRF) and 10% of duty cycle, has been obtained by five-way radial waveguide power c...

This paper presents a new variant of broadband Doherty power amplifier that employs a novel output combiner. A new parameter αα is introduced to permit a generalized analysis of the recently reported Parallel Doherty power amplifier (PDPA), and hence offer design flexibility. The circuit prototype of the new DPA fabricated using GaN devices exhibits maximum drain efficiency of 85% at 43-dBm pea...

This paper presents holistic design of a novel 4-way differential power-combining transformer for use in mm-wave power-amplifier (PA). The combiner with an inner radius of 25 um exhibits a record low insertion loss of 1.25 dB at 83.5 GHz. It is designed to simultaneously act as a balanced-to-unbalanced converter, removing the need for additional BALUNs typically required in differential circuit...

The frequencyand time-domain expressions are derived for the signal-to-noise power ratio (SNR) of an ideal Rake combiner output in a direct sequence spread spectrum (DSSS) mobile communication system. The derived SNR expressions make it possible to estimate the SNR statistics after Rake combining for an arbitrary spreading chip rate in the frequencyselective multipath channel. key words: spread...

In this paper, the fabrication method of a pump/signal (6 + 1) × 1 combiner based on large-core (48 μm) multimode signal fiber is introduced. Since not tapered in production, and an effective feedback alignment adopted during splice process, degradation ratio M2 value light only about 5% after passing through beam combiner. addition, with help home-made combiner, counter-directional tandem-pump...

Active power filter (APF) has now become a mature technology for harmonic and reactive power compensations in two-wire (single phase), three-wire (three phase without neutral), and four-wire (three phase with neutral) ac power networks with nonlinear loads. This paper presents a study on three different adaptive algorithms for active power filtering applications. These algorithms are adaptive l...

Wireless broadband digital communication systems are facing more and more critical power efficiency problems. Crest Factor (PAPR) is reported to be in 10-12dB range for WiMAX 802.16e systems implementing OFDM IFFT-1024 and 64-QAM modulation. In this work, outphasing (LINC) and Polar transmitter architectures are investigated and compared with Direct Conversion architecture. Complete system solu...