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We have developed a electronically reconfigurable 4×4 switch matrix for satellite communications at Ka-band downlink frequencies (17 … 22 GHz), utilizing low-temperature co-fired ceramic multilayer technology. During a successful one-year on-orbit verification aboard a German test satellite, the switch matrix showed continuous reliable operation and achieved the technology-readiness level (TRL = 9)...
We have developed a compact, high-performance, mechanically robust reconfigurable microwave switch matrix as well as peripheral components such as diode driver, voltage controlled oscillator, and power detector modules for satellite applications using the low temperature co-fired ceramics technology (LTCC) and hybrid integration of integrated circuits. In order to verify the technology for space applications,...
This paper presents designs for reconstruction filters suitable for a class-S power amplifier operating at a centre frequency of 900 MHz. Previously, we presented analytical comprehensive comparison of doubly and singly terminated filters and proved mathematically that only singly terminated filters owing to their constant input impedance can fulfil the requirements of current-mode switching amplifiers...
This paper presents the design of a reconstruction filter for a class-S power amplifier. Previously, a few doubly terminated filters for a switched-mode amplifier system were presented, but measurement results showed significant ripples up to 3 dB in output power. This effect can be explained by the current mode final stage acting like a current source with infinite internal impedance, thus demanding...
Cognitive radio applications require reconfigurable RF air interfaces. We present here the design of a reconfigurable decoupling and matching network (DMN) for a cognitive multi-band antenna array. The antenna array operates at three selected frequencies of GSM900, GSM1800 and IEEE 802.11b/g. The role of the DMN is to define radiation patterns at the input ports, decouple array elements, and improve...
The need for efficiency improvement of conventional class-AB-amplifiers when used with non-constant envelope modulations has set up interest in introducing switch mode amplifiers in the GHz operating frequency range. In order to be suitable for the amplification of arbitrarily modulated signals, a one-bit modulator is required at the input of the switch mode amplifier. Beside bandpass delta sigma...
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