Deduct frequency

[0302986]

I am doing a AM receiver project.
Anyone can introduce a IC for me to do a deduction of frequency. This is the details:
1.Frequency A - Frequency B = Frequency C.
2.The frequency wanted is 455khz to 1.5Mhz.

Thanks.

 

[RadioRon]

I do not understand the term deduction in this context. Your equation
1.Frequency A - Frequency B = Frequency C
is Subtraction of frequency B from Frequency A.

In an AM receiver, this subtraction is typically done using a Mixer. Frequency A and Frequency B are input to the mixer.

A mixer multiplies Sin(A) x Sin(B) giving the result:

1/2[ Cos( A-B) - Cos (A+B) ]

Note that the term Cos (A-B) is the subtraction of one frequency from another to produce the Difference between the two. This is what you want.

There are many ICs for this job, or you can choose to use a transistor or even a diode.

(A Discusssion on Mixers)

See Figure 3 in the above link.

A mixer will generate more than one output frequency. In order to output only the A-B result, you need to filter the undesired products. In your case this would be done with a low pass or bandpass filter placed on the output of the mixer.

 

[0302986]

Thanks.

Thanks for the info. Any suggestion for what IC should I use?

 

[Nigel Goodwin]

I suggest you study superhet radio circuits, a simple bipolar transistor is the most common method, often self-oscillating as well.