Antenna design for fm transmitter

1. Ground pole Antenna    

2. Half-Wave Dipole Antenna

1. Ground pole Antenna(GP)

This Antenna is most widely used all over the world. For example, when you see a police car it has a transmitter with Ground Pole Antenna The body of car serves as ground). It accepts load from 50 ohm source and has larger power output than Half-Wave Dipole Antenna.

Frequency	Radiator - B	Radials - A
108MHZ	660	693
104MHz	684	720
100MHz	713	749
90MHz	792	819

 2. Half-Wave Dipole Antenna Or Open Dipole Antenna

It accepts load from 75 ohm source and has much smaller power output than Ground Pole Antenna. Use this antenna only when you don't have GP Antenna.

Construction: Two aluminum rods ,each of length "L" in meters are joined together through an insulator as shown in fig. From center, 75 ohm cable is feeded just like ordinary TV antenna.