A Multimode Cellular Radio

A flexible, multimode radio transceiver for global system for mobile communications, enhanced data rates for global evolution, and wide-band code-division multiple access is presented. The receiver uses low-IF and direct-conversion concepts with an integrated notch filter to adapt to the different requirements. The polar transmitter includes several innovations to provide a flexible solution that eliminates the external SAW filters traditionally needed.     

Polar Transmitters for Wireless Communications

Future wireless communications will require multimode radio transceivers. This article looks at two possible transmitter architectures: direct upconversion and polar modulation. A brief review of the direct upconversion approach reveals some key limitations. This leads to a detailed study of the polar transmitter focusing on its operation, design challenges, and potential benefits. Its multi- mode capability and low power consumption are illustrated by a prototype design of a GSM, EDGE, and WCDMA polar transmitter. The efficiency of the polar transmitter is shown as a key enabler of future systems using OFDM modulation with high peak-to-average signals.     

A Computer Calculation of the Far Field Radiation Pattern of an Antenna Array

A computer program has been investigated and developed for the calculation of the far field radiation pattern of an antenna array. This paper contains an IBM 360/65 program for the calculation of the far field pattern with accuracy checks on the pattern obtained by using radio stations KXIC and WSUI, both located in Iowa City, Iowa, as assumed normals. Two theories of solving the far field calculation problem with the SDS-92/TR-48 hybrid computer are submitted.