Circulator
APPLICATION NOTE
Circulators and Isolators, unique passive devices
AN98035
Philips Semiconductors
Circulators and Isolators, unique passive devices
Application Note AN98035
0. Contents 1. 2. 3. 4. Introduction Definitions Behaviour of ferrites Principles of operation and construction 4.1 Resonance isolator 4.2 Field displacement circulator 4.3 Phase shift circulator 4.4 Faraday rotation circulator 4.5 Ring circulator 4.6 Junction circulator 4.7 Edge guided mode circulator 4.8 Lumped element circulator 5. Charcteristics 6. Correlation of parameters of a symmetrical 3-port-circulator 6.1 The lossless symmetrical 3-port-circulator 6.2 The lossy symmetrical 3-port-circulator 7. Applications 7.1 Decoupling of generator and load 7.2 Decoupling of amplifier stages 7.3 Decoupling of a transmitter or receiver from its antenna 7.4 Transmitter and receiver on the same antenna 7.5 Combiner for 2 or more transmitters in the VHF and UHF 7.6 Combiner for radio links 7.7 Combining amplifier stages in a solid-state transmitter 7.8 Operation of one-port-amplifiers 7.9 Locking and priming of oscillators 7.10 Variable attenuator and phase shifter Bibliography 1 1 2 7 7 8 9 10 11 11 13 14 16 17 17 19 21 21 22 22 23 23 26 26 27 27 28 29
1998 Mar 23
2
Philips Semiconductors
Circulators and Isolators, unique passive devices
Application Note AN98035
1. Introduction Circulators and isolators are passive devices used in modern rf and microwave equipment since some decades. By using them the stability, performance, and reliability of the systems can be improved, and often better and cheaper solutions are possible. In addition, in certain applications, e.g. one-port-amplifiers, the use of circulators is a must. This booklet will help you to understand these important devices and give you some hints to use them effectively.
2. Definitions
Fig.1: Energy flow in
a. a 3-port-circulator b. a 4-port-circulator
The circulator is defined as a passive device with 3 or more ports, where
Circulators and Isolators, unique passive devices
AN98035
Philips Semiconductors
Circulators and Isolators, unique passive devices
Application Note AN98035
0. Contents 1. 2. 3. 4. Introduction Definitions Behaviour of ferrites Principles of operation and construction 4.1 Resonance isolator 4.2 Field displacement circulator 4.3 Phase shift circulator 4.4 Faraday rotation circulator 4.5 Ring circulator 4.6 Junction circulator 4.7 Edge guided mode circulator 4.8 Lumped element circulator 5. Charcteristics 6. Correlation of parameters of a symmetrical 3-port-circulator 6.1 The lossless symmetrical 3-port-circulator 6.2 The lossy symmetrical 3-port-circulator 7. Applications 7.1 Decoupling of generator and load 7.2 Decoupling of amplifier stages 7.3 Decoupling of a transmitter or receiver from its antenna 7.4 Transmitter and receiver on the same antenna 7.5 Combiner for 2 or more transmitters in the VHF and UHF 7.6 Combiner for radio links 7.7 Combining amplifier stages in a solid-state transmitter 7.8 Operation of one-port-amplifiers 7.9 Locking and priming of oscillators 7.10 Variable attenuator and phase shifter Bibliography 1 1 2 7 7 8 9 10 11 11 13 14 16 17 17 19 21 21 22 22 23 23 26 26 27 27 28 29
1998 Mar 23
2
Philips Semiconductors
Circulators and Isolators, unique passive devices
Application Note AN98035
1. Introduction Circulators and isolators are passive devices used in modern rf and microwave equipment since some decades. By using them the stability, performance, and reliability of the systems can be improved, and often better and cheaper solutions are possible. In addition, in certain applications, e.g. one-port-amplifiers, the use of circulators is a must. This booklet will help you to understand these important devices and give you some hints to use them effectively.
2. Definitions
Fig.1: Energy flow in
a. a 3-port-circulator b. a 4-port-circulator
The circulator is defined as a passive device with 3 or more ports, where