Wireless# Guide to Wireless Communications 2ed dard be Review Questions 1. What is the difference between a filter and a mixer? What is the purpose of guardbands? 2. 3. As you know, amplifiers are used in receivers to increase the amplitude of the analog signal received by the antenna, so that it can be properly detected and the original modulating signal can be extracted. What is the purpose of using an amplifier in a transmitter? 4. What does an amplifier need in order for it to be able to make the output signal stronger? 5. Which type of device is used to allow only frequencies in a certain range to pass through? Lab 3-2 Multiple Access Objectives This lab is designed to help you understand the concepts employed in communications systems, such as multiple access, full-duplex, etc. After completing this lab, you should be able to: Explain the characteristics of different radio systems. Describe the purpose of a multiple access system. List different types of communications systems. January 2020 Page 3 -5