RF and Microwave Circuit and Component Design for Wireless Systems

CHAPTER TWO

General Wireless Systems

2.1 INTRODUCTION

Portable wireless service has it roots in the mobile radio communication. Initial application of the radio was in the fixed services within which both receivers and transmitters were fixed in location. The demand for smaller, efficient, and rugged systems increased with the advent of two-way communication in moving vehicles, ships, and planes. Semiconductor technology rose to the challenge, as the size and weight reduction became very important. When the idea of combining the two-way radio and telephone services materialized, the market opportunities for portable products soared significantly. The potential of telephone service from a moving vehicle ignited a whole new wireless market. As the number of subscribers to this service increased, the two-way radio capacity was used up, and the concept of cellular radio system was born [1]. Cellular radio system designers developed better frequency reuse techniques, and analog radio systems were implemented. Regulatory agencies have allocated several frequency bands for wireless applications over the years. During the last decade, many innovative portable communication products were introduced with dramatic reduction in weight, size, and cost. The difference in the rules stipulated by regulatory agencies in different countries led to many different standards around the world.

Another market segment that is emerging very rapidly is in the short-range wireless access applications. A ...