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Proposed Method for T/R Duplexing in a TDMA Power Booster

IP.com Disclosure Number: IPCOM000010860D
Original Publication Date: 2003-Jan-28
Included in the Prior Art Database: 2003-Jan-28
Document File: 2 page(s) / 40K

Publishing Venue

Motorola

Related People

Gadi Shirazi: AUTHOR [+3]

Abstract

This paper describes a novel method of duplexing uplink and downlink signals when applying an external power booster to a TDMA cellphone or 2-way radio.

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Proposed Method for T/R Duplexing in a TDMA Power Booster

By Gadi Shirazi, Zami Schwartzman & Haim Friedlander

Introduction

This paper describes a novel method of duplexing uplink and downlink signals when applying an external power booster to a TDMA cellphone or 2-way radio.

The common approach for implementing a power booster is shown in Figure 1 below.

 

Figure 1 – Functional Block Diagram of Existing Solution

When the cellphone (10) is in transmit mode, the transmitted signal enters port “c1” of Duplexing Filter 1 (20). This filter passes signals in the uplink frequency band to port “a1”, which is connected to the input of a Power Amplifier (PA) (30). The output of the Power Amplifier feeds port “a2” of Duplexing Filter 2 (40), which passes signals in the uplink frequency band to port “c2”, which is connected to an antenna (50). The antenna radiates the signal, which is then received by the cellular base station.

When the cellphone is in receive mode, signals in the downlink frequency band arrive at the antenna and enter Duplexing Filter 2 at port “c2”. This filter passes signals in the downlink frequency band to port “b2”, while maintaining isolation from port “a2”. The signal then reaches port “b1” of Duplex Filter 2, which passes signals in the downlink frequency band to port “c1”, while maintaining isolation from port “a1”. The signal then enters the cellphone, where it is received and processed as needed.

Problems To Be Solved and Known Solutions

The known solution, which i...