How to improve I/Q mismatch ?

Status
Not open for further replies.
C

ccw27

Full Member level 5
Joined
Oct 13, 2004
Messages
267
Helped
14
Reputation
28
Reaction score
6
Trophy points
1,298
Activity points
2,558
Can anyone provide me references on how to improve I/Q mismatch?

Thanks
 

improve iq mismatch

In RF design, commonly phase shifting network contribute primarily to I/Q mismatch, using octet phase generation would help in compensenting it.

Rgds
 
Reactions: LeonLi

    L

    LeonLi

    Points: 2
    Helpful Answer Positive Rating
phase amplitude mismatch

hi hrkhari, can you talk more about octet phase generation or provide reference?
Also I know you can also perform digital pre-distortion, is there any other method other than digital?

Thanks
 

layout i/q mismatch

1/4 λ microtrip line can produce 90-degree phase shift
 

i/q mismatch

have you ever try polyphase filter?
 

iq mismatch polyphase

y can use the digital technology to overcome the analoge IQ mismatch,

but if y tell me the concrete condition ,i can recommend some device with good IQ match
 

iq view mismatch filter

Hi there
There are 2 types of mismatch:
-amplitude
-phase

If you maintained nice electrical length between I and Q inputs then the main thing to do is adjust amplitude of one channel in respect to the other.
If you need more compensation, the phase needs to be adjusted. In a measuring setup it is easy.... just fool around with some different lenghts of coax in one channel. In a real application this is not possible.
A sort of calibration routine might help to adjust amplitude & phase. This calls for software.

rgds

Mike
 

polyphase filter i/q mismatch

The requirement for I/Q mismatch depends on the modulation. The BPSK/QPSK could tolerate more phase/amplitude mismatch than 8 PSK or 16 QAM. Based on your system, I/Q mismatch may be compensated at the baseband using DSP.
 

i/q mismatch polyphase

Hello,

There is this doc at Tropian on the error sources in an IQ modulator:
**broken link removed**

It can indicate which are the most important error terms that need to be corrected.
 

Re: I/Q mismatch

Hi,

Improving I/Q balance- Some issues to consider:
- Good quadrature phase balance (polyphase filter, divide-by-2 or 4)
- Good amplitude balance (limiting in some cases)
- Symmetry in layout critical (use dummies if necessary)
- Calibration if very high performance required by your system

All the best
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…