Ld

L.C.N. de Vreede

208 records found

An implementation strategy for high-power, high resolution, fully digital transmitters (DTX) is proposed. It is based on a high-speed CMOS controller featuring a high-density flip-chip interconnect to an LDMOS power MMIC containing large arrays of custom low-VT LDMOS gate segment ...

This article introduces a single-supply balun-first three-way parallel Doherty power amplifier (PA) tailored for millimeter-wave (mm-wave) fifth-generation (5G) applications. It incorporates a bandwidth enhancement technique that widens the operational frequency range, enhan ...
A wideband harmonic rejection voltage-domain mixer using resistive scaling is presented with excellent linearity and high IF bandwidth. Thin-oxide devices with constant gate-to-source voltages (VGS) are utilized to maximize the switching linearity. A novel switching core topology ...
Digital predistortion (DPD) enhances signal quality in wideband radio frequency (RF) power amplifiers (PAs). As signal bandwidths expand in modern radio systems, DPD's energy consumption increasingly impacts overall system efficiency. Deep neural networks (DNNs) offer promising a ...
The RF performance of current-scaling digital transmitters (DTX) with polar, unsigned Cartesian, signed Cartesian, and multiphase architectures have been compared regarding power utilization of their output-stage switch banks and drain efficiency. The analysis includes various sw ...

OpenDPD

An Open-Source End-to-End Learning & Benchmarking Framework for Wideband Power Amplifier Modeling and Digital Pre-Distortion

With the rise in communication capacity, deep neural networks (DNN) for digital pre-distortion (DPD) to correct non-linearity in wideband power amplifiers (PAs) have become prominent. Yet, there is a void in open-source and measurement-setup-independent platforms for fast DPD exp ...
This article introduces an N-way chain-weaver balanced power amplifier (PA) for millimeter-wave (mm-wave) phased-array transmitters (TXs). Taking advantage of the proposed combining network, an embedded impedance/power sensor is implemented, which can be utilized for output power ...
This article presents a wideband blocker tolerant receiver (RX) for fifth-generation (5G) user equipment applications. Two programmable zeros around the channel bandwidth are introduced to sufficiently suppress the close-in blockers of 5G applications. Since the effect of zeros g ...
Recently, the so-called sub-6GHz band of the 5G new radio (NR) has been extended to 7.125GHz to address the relentless customer demand for higher data-rate communication. This demands a new design approach for the local area base-station (LA-BS) receivers (RXs) to cover a wide op ...
This paper proposes a power amplifier (PA) correction technique to recover from load mismatch. It utilizes a main PA, two auxiliary PAs, and a coupler. By adjusting the input drive levels of the PAs it can recover the output power and to a great extent the efficiency of the main ...
A current-mode direct-digital RF modulator (DDRM)-based transmitter (TX) architecture is proposed in this article for energy-efficient wireless applications. To demonstrate its key principles, a 2×13 bit demonstrator is implemented in a 40-nm CMOS technology. This DDRM can operat ...
This paper presents a 40nm CMOS mm-wave 3-way Doherty power amplifier (PA) suitable for 5G mm-wave transmitters. It features a bandwidth-enhanced technique using a compact single-supply balun-first 3-way Doherty combiner. The realized front-end with a core area of 0.77 mm2deliver ...
This paper presents an advanced yet simple digital pre-distortion (DPD) technique for digital I/Q transmitters (DTXs). Exploiting the I/Q orthogonality, an effective 2×1-D DPD procedure is proposed to bypass the exhaustive 2-D search of the entire constellation diagram. Utilizing ...
This article presents an inverted Doherty power amplifier (IDPA) made load insensitive up to 2:1 voltage standing wave ratio (VSWR) across its fractional bandwidth with a very compact wideband impedance sensor embedded in its output power-combining network (OPCN). To correct for ...
This article presents a wideband, energy-efficient digital transmitter (DTX) suitable for multi-mode/multi-band wireless communication applications. It features various operation modes comprising Cartesian (Modes-1/-2) and multi-phase (Modes-3/-4) configurations utilizing LO cloc ...
By introducing three different techniques, this article, for the first time, presents a wideband highly linear receiver (RX) capable of handling blocking scenarios in fifth-generation (5G) microcell base station applications. First, a parallel preselect filter is introduced to sa ...
Recent sub-6GHz receivers (RXs) attempted to realize RF channel selection at the RX input for suppressing large close-in blockers. Although mixer-first RXs can achieve sharp RF filtering and good out-of-band (OOB) linearity, they suffer from large noise figure (NF) and high LO le ...
This work presents an ultra-compact single-antenna FD/FDD transceivers front-end. It comprises a nonreciprocal circulator, RX, and an integrated power amplifier (PA). In the proposed circulator, we devise a ring quarter-wave transmission line topology with adjusted characteristic ...
This paper presents a low-loss load-insensitive Doherty power amplifier (DPA) technique. The proposed DPA is insensitive to ohmic load variation by adjusting its supply voltages and input drive of the main and peaking stages in a mirrored approach. Moreover, a low-loss tunable ma ...
To support wideband complex modulated signals and comply with the stringent requirements of modern communication standards in an energy-efficient manner, recently, digital transmitters (DTXs) have been explored to fully benefit from the high-speed switching and integration capabi ...