Most antennas are connected to the transmitter or receiver using coaxial cable
Impedance
Opposition to the flow of alternating current in a circuit
Represented by the letter “Z” and measured in ohms
Combination of resistance, inductance, and capacitance of the circuit
Cable’s impedance must match that of the transmitter circuit as well as that of the antenna
You must consider the signal loss caused by the connector and by the cable itself