Advanced Bits-In RF-Out Transmitters

The demand for faster mobile access and higher data throughput drives the evolution of wireless cellular communication, requiring larger modulation bandwidths and higher-order modulations and necessitating more efficient and flexible transmitter systems.<br/>Simultaneously, the advancements in nano-scale CMOS technologies have made transistors...

A Wideband Energy-Efficient Multi-Mode CMOS Digital Transmitter

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 clocks with different duty cycle in the interleaving/non...

A Current Re-Use Quadrature RF Receiver Front-End for Low Power Applications: Blixator Circuit

This article presents the theory and implementation of a quadrature and differential RF front-end receiver. Combining balun, low-noise amplifier (LNA), mixer, and oscillator in a single stage, the proposed circuit, named the Blixator, is well suited for low-power applications. The baseband's transimpedance amplifier (TIA) also shares part of...

A Wideband Two-Way Digital Doherty Transmitter in 40nm CMOS

A 40nm CMOS wideband digital Cartesian push-pull inverted Doherty operating in class-E is presented. Wideband Doherty operation is achieved over a 1.9-to-3GHz frequency band, using an off-chip power combining network. The fully digital transmitter (DTX) provides 25.3dBm peak power with a drain/DTX line-up efficiency (DE/SE) of 58.7%/44.9%,...

A 76.5-92.6 GHz CMOS LNA Using Two-Port kQ-Product Theory for Transformer Design

This letter presents a convenient approach based on the two-port kQ-product theory to analyze the influence of interwinding capacitive coupling on the efficiency of the transformer. It is demonstrated that a transformer with proper size can benefit from the interwinding capacitive coupling to maximize its efficiency at a desired frequency....

Design of Current-Mode RF/mm-wave Front-Ends

This thesis investigates the performance limits and design challenges of two current-mode front-end concepts that target WiFi and mm-wave 5G applications, respectively. The first concept is a power amplifier (PA), which operates at 2.4GHz and is driven by a direct-digital RF modulator (DDRM). A design for the PA, which also includes a parallel...

A Wideband Four-Way Doherty Bits-In RF-Out CMOS Transmitter

We present a wideband, 12-bit four-way Doherty Cartesian digital transmitter (DTX) featuring an innovative 50%-LO signed I/Q interleaved up-conversion technique that enables close to perfect orthogonal I/Q summation. The DTX incorporates a compact four-way lumped-element Doherty power combining network to enhance its average efficiency at...

Wideband high-efficiency Doherty Power Amplifiers

All-Digital I/Q RF-DAC

Due to the severe cost pressure of consumer electronics, a migration to an advanced nanoscale CMOS processes, which is primarily developed for fast and low-power digital circuits operating at low supply voltages, is necessary, but it forces wireless RF transceivers to exploit more and more digital circuitry. These basic CMOS properties tend to...

A Wideband 2x13-bit All-Digital I/Q RF-DAC

This paper presents a wideband 2 13-bit in-phase/quadrature-phase (I/Q) RF digital-to-analog converter-based all-digital modulator realized in 65-nm CMOS. The isolation between I and Q paths is guaranteed employing 25% duty-cycle differential quadrature clocks. With a 1.3-V supply and an on-chip power combiner, the digital I/Q transmitter...

Wideband High Power Doherty Amplifiers

Currently the Doherty Power Amplifier (DPA) is replacing the traditional Class B amplifier in base-station and broadcast applications, as such becoming the preferred choice of industry due to its simplicity and high efficiency performance. In spite of its success, so far practical DPA implementations can provide only a very limited RF bandwidth,...

Enhanced Techniques for the Design and Characterization of RF Power Amplifiers

Integration of a Pulse Generator on Chip Into a Compact Ultrawideband Antenna

For impulse radio ultrawideband communications an “antenna plus generator” system is co-designed and an on chip generator is integrated into the antenna. This approach does away with the need for intermediate transmission lines conventionally placed between an RF device/generator and an antenna and therefore eliminates the need for a balun,...