The Transmitter Output Power is defined as the power produced in to a 50 Ohm load connected at the radio antenna port.
In transmit mode, the Synthesizer produces the desired Tx frequency with the FM modulation (speech or data) super-imposed. This part is called the Exciter. The transmitter then amplifies this signal up to the final power level to be transmitted, after which the signal passes through the Tx/Rx Switch before being filtered to remove any unwanted harmonics. Ideally then, all that is transmitted is the desired signal at the required... Continue Reading
Before we get into the detail of each RF performance parameter, this week, let us discuss the parts that make up a typical radio. This is absolutely crucial to understanding the parameters that affect RF performance.
Shown below is a very simplified block diagram of the RF part of a typical Tait FM Mobile or Portable radio. Two commonly used abbreviations are introduced here -Tx (ie: Transmitter), and Rx (ie: Receiver). These abbreviations will be used throughout the remainder of this series.
The heart of the RF section is the Synthesizer. Here,... Continue Reading
We are starting a new series of posts on the blog under the title – RF Performance Parameters. The purpose of this series is to:
- Introduce the deci-Bel, the unit relevant to RF measurements.
- Describe the major RF performance parameters that are used to benchmark the performance of both the Transmitter and Receiver sections of a radio.
- Compare the various performance levels of a Portable radio, a Mobile radio and a Base Station in terms of these parameters.
- Examine how these performance parameters manifest themselves within a radio system, ie: a network... Continue Reading