How Can You Design an FM Radio Receiver to Favor One Station Over Another?

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SUMMARY

The discussion focuses on designing an FM radio receiver circuit that prioritizes KONG-FM at 96.6 MHz over KRUD-FM at 96.5 MHz. The circuit must achieve maximum power response to KONG-FM while limiting the power from KRUD-FM to 1% of that received from KONG-FM. The design requires an inductor of 1.00 µH, and participants discuss the necessary calculations for capacitance (C) and resistance (R) to meet these specifications, utilizing formulas such as wL = 1/wC and Pavg = (Irms^2)*R.

PREREQUISITES
  • Understanding of L-C-R circuit design
  • Familiarity with FM radio frequency calculations
  • Knowledge of power calculations in electrical circuits
  • Proficiency in using formulas for inductance and capacitance
NEXT STEPS
  • Calculate the required capacitance (C) for the circuit using C = 1/(w^2*L)
  • Determine the resistance (R) that meets the power delivery requirements
  • Explore the impact of varying inductance on circuit performance
  • Research advanced filtering techniques for FM receivers
USEFUL FOR

Electrical engineering students, hobbyists designing radio receivers, and professionals working on RF circuit optimization will benefit from this discussion.

sbe07phy
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Homework Statement


Designing an FM Radio Receiver. You enjoy listening to KONG-FM, which broadcasts at 96.6 MHz. You detest listening to KRUD-FM which broadcasts at 96.5 MHz. You live the same distance from both stations and both transmitters are equally powerful, so both radio signals produce the same 1.0 V source voltage as measured at your house. Your goal is to design an L-C-R radio circuit with the following properties: i) It gives the maximum power response to the signal from KONG-FM; ii) the average power delivered to the resistor in response to KRUD-FM is 1.00% of the average power delivered to KONG-FM. This limits the power received from the unwanted station, making it inaudible. You are required to use an inductor with L = 1.00 µH.

a) Find the capacitance C that satisfies the design requirements?
wrong check mark F
(b) Find the resistance R that satisfies the design requirements?


Homework Equations


wL = 1/wC when at max. power and the angle phi = 0 degrees
but i am having trouble with the 1% of the power part of the problem and how to involve that into this.
96.6 MHz = 606955700.7 rad/sec
96.5 MHz = 606327382.1 rad/sec
L = 1.0e-6 H
V = 1.0 V
C?

The Attempt at a Solution


wL=1/wC
C =1/(w^2)L
How do I involve the power into this?
P=IV
Pavg = 0.5*Imax*Vmax*cos(phi)
Pavg = Irms*Vrms*cos(phi)
Pavg = (Irms^2)*R
 
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This is a screenshot of the solution from a PDF that I found. I had a little bit of trouble with the same problem.

This helped me figure it out.

Came across this in google, I am probably too late though.
 

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