Nir Tal

An EDGE transmitter with mitigation of oscillator pulling

We propose a polar transmitter architecture that is robust to modulation-induced injection pulling of its RF oscillator by means of a built-in self compensation. A mathematical model is presented for the injection pulling mechanism, which incorporates a digitally-controlled delay circuit that minimizes injection pulling by adjusting the overall phase shift in the parasitic path between the final amplitude modulation stage (aggressor) and the RF oscillator (victim). The technique is verified in a 65-nm CMOS GSM/GPRS/EDGE SoC demonstrating compliant error vector magnitude (EVM) and modulation spectral-mask performance over process and temperature.

A 45nm CMOS near-field communication radio with 0.15A/m RX sensitivity and 4mA current consumption in card emulation mode

Near Field Communication (NFC) is an emerging technology that is penetrating the mobile phone market rapidly. Compliance to multiple NFC standards [1-3] requires designs to support wide dynamic range of field (0.15 to 12A/m), multiple data rates (1.65 to 848Kb/s), various modulation transition times (0.01 to 8usec), wide range of modulation indices (8 to 100%) and line coding techniques (Manchester, NRZ, Modified Miller and PPM). Also, support for small antenna size and very low power card emulation (tag) operation results in additional design constraints. The solution described here integrates all the NFC functions on a multi-IP connectivity SOC in 45nm CMOS.

Coexistence Performance Enhancement Techniques for DRP Based WLAN/WPAN and Cellular Radios Collocated in a Mobile Device

The incorporation of Bluetooth and Wireless LAN transceivers in a mobile devices poses design challenges associated with their coexistence with the cellular transceiver, as they often need to operate concurrently and their close proximity is inevitable. We present some recently developed techniques that transform the RF and analog circuit design complexities, typically encountered when targeting enhanced coexistence performances, into the digital domain, and demonstrate how these techniques allow the concurrent operation of two transceivers without each of them adversely impacting the performance of the other. The ideas presented have been implemented in a commercial Bluetooth single chip transceiver offered by Texas Instruments.