Whitepapers

SISO to MIMO: Moving Communications from Single-Input

Commercial radio technology has reached an inflection point, similar to the transition from analog to digital, when we invented a whole range of digital technology; now we’re moving from single carrier technologies, where we transmit one digital symbol at a time, to a new paradigm, where we’re potentially transmitting hundreds of symbols simultaneously.
Read More

Power Amplifier Savings with DC-DC Converters in GSM-GPRS-EDGE Mobile Handsets

This article is targeting on a technology of adjustable DC-DC converters, which can be implemented with GSM-GPRS-EDGE power amplifiers, as it is already widely used in CDMA/WCDMA handsets. Simulations show why this has not been used so far and how important the battery average consumption savings could be, with this low complexity technology used instead of a polar-loop architecture, which is under high effort recently in many companies.
Read More

LDMOS Transistors in Power Microwave Applications

More than ten years ago LDMOS transistors were introduced as a replacement of bipolar transistors for RF power applications [1,2]. Nowadays LDMOS technology is the leading RF power technology for base station applications, in particular for GSM-EDGE applications at 1 and 2 GHz, WCDMA applications at 2.2 GHz and more recently for WiMax applications around 2.7 GHz and 3.8 GHz.
Read More

Integer-N PLL Local Oscillator for Satellite Telecommand Receiver

This article describes the design and implementation of L-band frequency synthesizer based Local Oscillator to down-convert the uplink signal in a Telecommand Satellite Digital Receiver. An Integer-N PLL scheme was implemented to achieve a compact and low power module. The Local Oscillator when tested with the Receiver successfully achieved all performance parameters for satisfactory operation of the total system.
Read More