My biggest engineering project thus far is this, my 1.6 MHz AM Transceiver that I built during summer break of 2025 which achieved an approximately 20-meter transmission distance. Ever since my first signals and systems class this past fall, I have been curious about communication systems and how they work. So I figured this summer could be an opportunity to enhance my understanding by making one of my own. It could not possibly have been a more rewarding experience, as it was a culmination of all my knowledge from various electrical engineering classes I have taken. The purpose of AM radio is to facilitate communication between those who are far away by using electromagnetic waves. For physics reasons it is optimal to broadcast using EM frequencies that are much greater than the frequency range occupied by message signals, such as voice or music. Directly sending out message signals as EM radiation would be massively inefficient and significantly impact the range of the radio system. Thus the need to encode the message signal within a higher frequency signal (called the carrier signal) becomes apparent. AM radio is just one method of encoding the message signal into the carrier signal. The amplitude of the carrier signal is modulated by multiplying it with the message signal, hence the name Amplitude Modulated. This produces the modulated signal, which is then sent out as EM radiation. On the receiving end, many EM signals are detected, so first a bandpass filter is applied to capture solely the modulated signal. Next this modulated signal is multiplied by a local oscillation of the same frequency as the carrier signal to shift the frequencies down back to the range where they can be heard by humans. Lastly, a lowpass filter is applied to kick out unneeded high frequency components. This method of AM signal processing is called synchronous detection and offers superior signal reconstruction compared to simpler methods such as envelope detection. Once I understood the theory behind how this technology worked, I moved to begin the design process. From my Junior Design courses I had known that the first step to designing a complicated system is to create a top-level block diagram to simplify the design process. This turned tackling a large task into tackling multiple smaller ones, which is much easier to do. The transmission side of the project can be broken down into four main blocks: 1) Message In, outputs an audio signal from either the onboard microphone or the AUX port at the user’s discretion. 2) Oscillator, outputs a 1.6 MHz carrier signal by use of a Wien-Bridge Oscillator with stabilization diodes. 3) Amplitude Modulator, takes the audio signal and the carrier signal and multiples them together to output an amplitude modulated signal. 4) Transmitter Amplifier, uses a non-inverting amplifier to increase the amplitude of the modulated signal before being transmitted through the antenna The receiving side of the project can be broken down into three distinct blocks: 1) Band-Pass Filter, uses a Sallen-Key filter for isolating the 1.6 MHz amplitude modulated signal. The gain of this block can be adjusted using a potentiometer, thereby controlling the volume of the final system output. 2) Receiving Multiplier, multiples the modulated signal with a local 1.6 MHz oscillation to shift the frequencies back towards the audible range. 3) Low-Pass Filter, a Sallen-Key Filter is used to eliminate non-audible frequencies for optimal message signal reconstruction. Overall, this project was very informative to my understanding of communication systems. It asked me to combine knowledge from Signals and Systems, Electronics, Junior Design, and Transmission Lines and ultimately synthesize something that represents my understanding of them all. At the end of the day, I am just simply happy to create something I can call my own.