Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Out of band stability of RF power amplifier

Status
Not open for further replies.

Mabrok

Full Member level 4
Joined
Mar 1, 2017
Messages
223
Helped
0
Reputation
0
Reaction score
1
Trophy points
18
Activity points
1,597
Hi,
I have designed doherty power amplifier for 3.4-3.6 GHz band. After many optimization process, I get the required specifications. However, the simulation results show instability at 500 MHz to 1 GHz (K<0), and at 1.4 GHz (K<1). For other frequencies from 0 to 6GHz the amplifier is stable. So, Is the instability at the above mentioned frequencies which are out of band frequencies will affect the performance of my design especially in the fabrication process ? as for simulation I have not see any effect. Thanks in advanced
 

Hi,
I guess it will affect. Simulate transient oscillation is not obvious. It is not always easy to start the oscillation in simulation, but in real life the circuit can generate out of band oscillation which produce harmonics, consume power, cause reflections.
 

Have you ever drawn Load and Source Stability Circles for the bands which are root cause of instability ?? There may be a small portion/extreme region that makes the amplifier unstable..
That's sometimes acceptable..
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top