Whitepapers

Reinventing the Transmit Chain for Next-Generation

Upcoming generations of radio access standards are placing high demands on the RF transmit chain, requiring significant improvements in size, integration, and functionality while improving power efficiency for multimode wireless devices. To date, trends in RF integration have been to add redundant circuits to accommodate new standards, packing more complexity into the circuit, and then shrinking it. However, this approach often requires a necessary compromise in performance and yield, with physical limits in terms of overall size reductions. A new approach is needed that incorporates a streamlined architecture to accommodate the additional levels of complexity due to multimode functionality, while improving efficiency, yield, and size, and meeting regulatory compliance.
Read More

Super-regenerative Receiver

This article describes the super-regenerative receiver (SRR), a device widely used in short distance telemetry and remote control applications. The difficulty in modeling the regenerative behavior served as the basis for “cut and try” methodology based on results obtained from the simplified model using a conventional approach. This work presents the SRR behavior to practical implementations by dynamically controlling the injection-mode levels of the super-regenerative oscillator (SRO) for optimum sensitivity and dynamic ranges.
Read More

Future Technologies and Testing for Fixed Mobile Convergence, SAE and LTE in Cellular Mobile Communications.

The Mobile Communications industry is currently developing standards and solutions for the next steps in the evolution of mobile networks. This introduction looks at the fundamental radio and network technologies being introduced in these steps, and how this is aligned into the future Fixed Mobile convergence (FMC) of the Next Generation Networks.
Read More

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