The end goal of the lab is to build a usable radio and an antenna is needed. Antennas come in different forms, such as, di- or monopole, horn, patch, loop and more. For simplicity, a loop antenna was built for the radio, to be precise, a square loop antenna. How? Pizza box and wire.

Using the pizza box and wire, the wire was wrapped around the pizza box to make a square loop around the box, the loop itself acts as an inductor. The inductor can receive signal through the magnetic field of the inductor, but adding a capacitor helps in picking the desired frequency. By adding a capacitor in parallel to the antenna, a resonant frequency occurs in the circuit, which can be adjusted by adjusting the value of the capacitor and inductor.

Changing the magnitudes of the capacitor and inductor can seem trivial, however, it is not the case, for the inductor at least. As there is no access in the lab to any sophisticated equipment that can change the inductance and the radio needs to be simple enough that it can be rebuilt at later time without access to any lab equipment, it is easier to have a set inductance and making the capacitor be a varying capacitor.