Patrick Cruise

All-digital PLL and transmitter for mobile phones

We present the first all-digital PLL and polar transmitter for mobile phones. They are part of a single-chip GSM/EDGE transceiver SoC fabricated in a 90 nm digital CMOS process. The circuits are architectured from the ground up to be compatible with digital deep-submicron CMOS processes and be readily integrateable with a digital baseband and application processor. To achieve this, we exploit the new paradigm of a deep-submicron CMOS process environment by leveraging on the fast switching times of MOS transistors, the fine lithography and the precise device matching, while avoiding problems related to the limited voltage headroom. The transmitter architecture is fully digital and utilizes the wideband direct frequency modulation capability of the all-digital PLL. The amplitude modulation is realized digitally by regulating the number of active NMOS transistor switches in accordance with the instantaneous amplitude. The conventional RF frequency synthesizer architecture, based on a voltage-controlled oscillator and phase/frequency detector and charge-pump combination, has been replaced with a digitally controlled oscillator and a time-to-digital converter. The transmitter performs GMSK modulation with less than 0.5/spl deg/ rms phase error, -165 dBc/Hz phase noise at 20 MHz offset, and 10 /spl mu/s settling time. The 8-PSK EDGE spectral mask is met with 1.2% EVM. The transmitter occupies 1.5 mm/sup 2/ and consumes 42 mA at 1.2 V supply while producing 6 dBm RF output power.

All-digital PLL and GSM/EDGE transmitter in 90nm CMOS

A 1.2V 42mA all-digital PLL and polar transmitter for a single-chip GSM/EDGE transceiver is implemented in 90nm CMOS. It transmits GMSK with 0.5/spl deg/ rms phase error and achieves -165dBc/Hz phase noise at 20MHz offset, with 10 /spl mu/s settling time. A digitally controlled 6dBm class-E PA modulates the amplitude and meets the EDGE spectral mask with 3.5% EVM.

The First Fully Integrated Quad-Band GSM/GPRS Receiver in a 90-nm Digital CMOS Process

We present the receiver in the first single-chip GSM/GPRS transceiver that incorporates full integration of quad-band receiver, transmitter, memory, power management, dedicated ARM processor and RF built-in self test in a 90-nm digital CMOS process. The architecture uses Nyquist rate direct RF sampling in the receiver and an all-digital phase-locked loop (PLL) for generating the local oscillator (LO). The receive chain uses discrete-time analog signal processing to down-convert, down-sample, filter and analog-to-digital convert the received signal. A feedback loop is provided at the mixer output and can be used to cancel DC-offsets as well to study linearization of the receive chain. The receiver meets a sensitivity of -110 dBm at 60mA in a 1.4-V digital CMOS process in the presence of more than one million digital gates

A digital-to-RF-amplitude converter for GSM/GPRS/EDGE in 90-nm digital CMOS

We present the first 90-nm digital CMOS RF power amplifier. This PA contains a large array of NMOS switches, and performs a direct digital-to-RF-amplitude conversion, filtering and buffering in a fully-integrated GSM/EDGE transmitter. Power control is fully digital. 40% efficiency is obtained at 10-dBm output power from 1.4 V and it occupies 0.005 mm/sup 2/.

A 24mm 2 Quad-Band Single-Chip GSM Radio with Transmitter Calibration in 90nm Digital CMOS

The RF transceiver is built on the Digital RF Processor (DRP) technology. The ADPLL-based transmitter uses a polar architecture with all-digital PM-FM and AM paths. The receiver uses a discrete-time architecture in which the RF signal is directly sampled and processed using analog and DSP techniques. A 26 MHz digitally controlled crystal oscillator (DCXO) generates frequency reference (FREF) and has a means of high-frequency dithering to minimize the effects of coupling from digitally controlled PA driver (DPA) to DCXO by de-sensitizing its slicing buffer.

A 0.8mm 2 all-digital SAW-less polar transmitter in 65nm EDGE SoC

EDGE is currently the most widely used standard for data communications in mobile phones. Its proliferation has led to a need for low-cost 2.5G mobile solutions. The implementation of RF circuits in nanoscale digital CMOS with no or minimal process enhancements is one of the key obstacles limiting the complete SoC integration of cellular radio functionality with digital baseband. The key challenges for such RF integration include non-linearity of devices and circuits, device mismatches, process parameter spread, and the increasing potential for self-interference that could be induced by one function in the SoC onto another.

A discrete time quad-band GSM/GPRS receiver in a 90nm digital CMOS process

We present the receiver in the first single-chip GSM transceiver that incorporates full integration of quad-band receiver, transmitter, memory, power management, dedicated ARM processor and RF built-in self test in a 90 nm digital CMOS process. The architecture uses direct RF sampling in the receiver and an all-digital PLL in the transmitter. The receive chain uses discrete-time analog signal processing to down convert, down- sample, filter and analog-to-digital convert the received signal. An auxiliary feedback is provided at the mixer output that can linearize the entire receive chain. The receiver meets a sensitivity of -110 dBm at 60 mA in a 1.4V digital CMOS process

A GSM/GPRS receiver front-end with discrete-time filters in a 90 nm digital CMOS

An RF receiver front-end for a GSM/GPRS radio system-on-chip in a 90 nm digital CMOS technology is presented. The circuit consisting of low noise amplifier, transconductance amplifier and switching mixer, offers 32.5 dB dynamic range with digitally-configurable voltage gain of 40 dB down to 7.5 dB. A series of decimation and discrete-time filtering follows the mixer and performs a highly-linear second-order low-pass filtering to reject close-in interferers. The front-end gains can be configured with an automatic-gain-control to select an optimal setting to form a trade-off between noise figure and linearity and to compensate the process and temperature variations. Even under the digital switching activity, noise figure at the 40 dB maximum gain is 1.8 dB and +50 dBm IIP/sub 2/ at the 34 dB gain. The variation of the input matching versus multiple gains is less than 1 dB. The circuit in total occupies 3.1 mm/sup 2/. The LNA, TA and mixer consume less than 15.3 mA at a supply voltage of 1.4 V.

Sigma-delta noise shaping for digital-to-frequency and digital-to-RF-amplitude conversion

In this paper, we describe a new architecture of high-speed multibit /spl Sigma//spl Delta/ noise shaping for digital-to-frequency conversion (DFC) and digital-to-RF-amplitude conversion (DRAC). The DFC and DRAC are instrumental in performing phase modulation (PM) and amplitude modulation (AM) of an RF polar transmitter. Since current biasing and continuous-time analog filtering of a conventional transmit modulator are avoided in this all-digital architecture, it is amenable to large-scale integration in an SoC realized in a digital deep-submicron CMOS process. The approach is demonstrated in the first single-chip fully-compliant GSM/EDGE transceiver realized in 90-nm CMOS.

A low-cost quad-band single-chip GSM/GPRS radio in 90nm digital CMOS

In this paper we present a quad-band single-chip GSM/GPRS radio in 90nm digital CMOS process based on the Digital RF Processor (DRP™) technology. This chip integrates all functions from physical layer to the protocol stack and peripheral support in a single chip RF SoC. The transmitter uses a low-area small-signal digital polar architecture merging amplitude and phase information directly in an RF DAC. The receiver is based on direct RF sampling and discrete-time analog signal processing. A dedicated internal microprocessor manages the digital RF controls to provide best achievable RF performances. The transceiver exceeds all 3GPP specifications demonstrating a receive NF of 1.8 dB and a margin of 8dB on TX spectral mask at 400 KHz offset in GSM850/900 bands. The transceiver is best-in-class in area and occupies only 3.8 mm2 of silicon area.