AE604 Advanced Electronics (AE) Individual Assignment – FM Radio Transmission Design

AE604 Section A – To Be Completed By The Student – PLEASE PRINT CLEARLY

AE604 Section B – To Be Completed By The Assessor

Intended Learning Outcomes assessed by this work.

Design, analysis and calculation of filter design, RF power amplifier, matching network (IMN & OMN) using smith chart, antenna matching, power calculation, Free space path loss (FSPL) estimates from Transmitter system to receiver device, layout considerations, practical components selection and complete circuit design.

AE604 FM Radio Transmission System

Figure 3 Power loss due to the moving vehicle, building blockage plot

Figure 1 shows a typical RF radio transmission station and Figure 2 shows a typical RF Radio Receiver Device. While Figure 3 shows the amount of additional loss to be considered in the path loss calculation due to the moving vehicle and building blockage at different location within the broadcast range. In Figure 3, a positive number refers to a power gain, while a negative number refers to a power loss.

The transmission station, as shown in Figure 1, up-convert audio frequency into a much higher frequency for long distance broadcast of up to 100km [2]. It has one-stage up-converter mixer with a local oscillator, two bandpass filter, two RF matching network and one matching transformer terminated with the RF transmission antenna.

The receiver device, as shown in Figure 2, down-convert RF frequency to audio frequency. It has a low-noise-amplifier (LNA), one bandpass filter(BPF), one lowpass filter(LPF), one down-converter mixer with local oscillator, a pre-amplifier and an audio amplifier.

The transmit antenna has a gain, Gt, of -0.75dBi to +0.75dBi [5] and the receive antenna has a gain, Gr, of -1.50dBi to 1.50dBi [5].

Consideration for building, movable vehicle blocking or cause the additional attenuation/loss to be included as per Figure 3 to be taken into account for the FSPL calculation. Student is to determine whether the received signal strength is sufficient and if it is not sufficient what should be done.

The receiver sensitivity of the receive section to ensure the circuit to function well requires a minimum of -90dBm to -60dBm [6] while the transmitter have a maximum transmit power of 0dBm to +40dBm [7].

Each student is assigned to use different FM radio frequency channels from 88MHz to 108MHz [1] and a different distance between the transmitter and receiver. The design, analysis, explanation and calculation to include the following:

1. Overall transmitter system explanation
2. Bandpass filter (BPF) design
3. Input matching network (IMN) design using smith chart
4. RF power amplifier design
5. Output matching network (OMN) design using smith chart
6. Antenna – matching quarter wavelength transformer
7. Power calculation from output of mixer to transmit antenna chain
8. FSPL to the receiver input calculation
9. Final complete circuit design with components values specified from output of the up-converter mixer to the transmit antenna.
10. Final presentation

Suggest a practical approach of the implementation. Consideration of using real world practical components for implementation is needed. RF amplifier chosen need to have the S-parameter given in the datasheet.

Also take into considerations the stray capacitance and stray inductance present in physical layout of the PCB traces and component placement.

Students could also discuss about the various signal fading experienced by FM radio broadcast including passing object such as car, building blockage, etc.

State any assumption used clearly and explain why such assumption is used.

The following tables will be given to the students:

1. Assigned frequency table
2. Assigned broadcast distance table for FSPL calculation
3. Assigned additional power loss/gain chart (Figure 3)
4. S-parameter table @ specific Vce/Ice
5. Transmit antenna gain (Gt) and Receive antenna gain(Gr)
6. Receiver Sensitivity
7. Transmit power

 Submit the report on due date. Wholesale copy of text & graphics from generative AI and from internet sources constitute plagiarism and student will be awarded zero marks.

Note: it is very important that the work submitted is an individual effort. The penalties for plagiarism are severe.

Keep a safe copy of all coursework submitted for reference.

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