90 degree phase shifter for a sine wave with variable frequency

[newbie_hs]

I need to design 90 degree phase shifter for a sine wave of amplitude 1V and frequency varies from 5Khz to 50Khz I found some solutions here itself.
In all those approaches amplitude varies with frequency.

I need constant amplitude at all these frequency range.May I know any circuit ideas.

 

[mtwieg]

The phase difference between the two outputs is 90 degree.Please correct me if I am wrong.
How will I connect this this to my system.
My system can take only one input which is a 90 degree phase shift of the I/P signal.
Below is my system block diagram

facepalm

This is why FvM clearly asked if a differential phase shift was acceptable.

The short answer is no, there's no way to create broadband phase shift with analog circuits.

However in practice there is probably no need to do so. If you explained why you need this phase shift and what role it plays in your system, it's likely we can find a way to get what you want.

@barry
I agree.Can I use this IC for my application.

No, that will not help you.

 

[newbie_hs]

If you explained why you need this phase shift and what role it plays in your system, it's likely we can find a way to get what you want.

I will check one more time with the team(Optics Team).What they told me is that they have an input sine wave of frequency which varies from 5K-50Khz and they need
a system which will do a 90 degree phase shift of this signal.I will discuss with them again,try to get the full information about their system and will update here.

 

[FvM]

Requirements aren't actually clear. Discussed all-pass chains are used for complex signals, e.g. speech or other audio. If you have a monofrequent sine, there are probably simpler methods. It's however no clear what's the significance of magnitude ("1V"). If the problem is only about keeping it constant, an ALC circuit can do the trick.

 

[newbie_hs]

ALC circuit

ALC means "Automatic Level Control (ALC) Circuit"Please correct me if I am wrong.
I will get the proper requirement tomorrow.

 

[FvM]

Yes

 

[newbie_hs]

I had a discussion with the team again.The requirement is same.Let me tell the requirement one more time here.
They have a sine wave of frequency 5Khz to 50Khz with an amplitude of 1V.I need to design a circuit which will phase shift this input signal by 90 degree.

 

[D.A.(Tony)Stewart]

push back on the team leader or Prof and ask for better specs.

phase error?
SNR? incl. harmonic distortion
power?
Vp or Vrms
analog or digital converted to analog
timeline?

 

[newbie_hs]

Phase error 0.5 degree(not finalized).
Even they don't have any idea about the other things.
First I need to make a simple proto

 

[D.A.(Tony)Stewart]

no idea after how much research with the internet or library?
what is the end game?

 

[dick_freebird]

An interesting problem for absolute phase accuracy whilst maintaining amplitude by AGC, is that amp BW may add its own phase lag dependence on the gain-setting (a fair bet when varying by either bias current or gain-node impedance).

 

[D.A.(Tony)Stewart]

What do you think of this ?

 

[FvM]

Output signal:
- should track input magnitude
- should maintain 1 V (pk, rms ?) independent of input magnitude
- either of both

 

[newbie_hs]

Output signal:
- should track input magnitude
- should maintain 1 V (pk, rms ?) independent of input magnitude
- either of both

I checked again if "output amplitude little less than 1V if also fine,we can amplify the phase shifted signal". this is what I received.Initial intention is to create phase shifted signal

 

[D.A.(Tony)Stewart]

Where does Sine in come from? Sig Gen, VCO? S/W?
It is better to create IQ from 2f then convert to sine or use Nxf then IQ then convert each to sine using R-DAC /N registers for perfect phase.
Do you agree?

Does DC bias matter?

 

[barry]

how fast does the frequency change? Or Is it static? What is the required response time? I’m thinking a digital solution might be simplest.

 

[newbie_hs]

Where does Sine in come from? Sig Gen, VCO? S/W?
It is better to create IQ from 2f then convert to sine or use Nxf then IQ then convert each to sine using R-DAC /N registers for perfect phase.
Do you agree?

Does DC bias matter?

Sine wave comes from Function generator.

--- Updated Friday at 3:10 PM ---

how fast does the frequency change? Or Is it static? What is the required response time? I’m thinking a digital solution might be simplest.

Sine wave frequency is 5Khz to 50khz

 

[D.A.(Tony)Stewart]

You could also make several fixed-f quadrature IQ-Sine oscillators Vp controlled by Vref or AGC (tbd) "Phase shift Oscillator"

https://tinyurl.com/2ya2zl83 <= online sim.

If you do not think harder about your design specs and answer my questions this is going to sound like an immigration interrogation.

 

[newbie_hs]

If you do not think harder about your design specs and answer my questions this is going to sound like an immigration interrogation.

Input is coming from external world like function generator.

 

[D.A.(Tony)Stewart]

Why is that so important? This is not a design goal or spec.

I am done here unless you can answer my previous questions, which I need not repeat.

 

[barry]

Sine wave comes from Function generator.

--- Updated Friday at 3:10 PM ---

Sine wave frequency is 5Khz to 50khz

That's not what I asked. I asked how fast the frequency changed, not what the range was.

Input is coming from external world like function generator.

You know, they make frequency generators with quadrature (90 degree) outputs...