File:Rhombic antenna diagram.svg

English: Diagram of radiation patterns of wire segments of a rhombic antenna, showing how it works. The rhombic antenna is a directional wire antenna used on MF and HF bands for shortwave reception. The antenna consists of a wire suspended above the ground in the shape of a rhombus, terminated at one end by a resistor equal the the wire's characteristic impedance, about 400 to 600 ohms, and at the other end connected to the feedline to the receiver. The rhombic is a travelling wave antenna, Each segment of the rhombus has a radiation pattern as shown (grey) having two lobes pointed forward at a certain angle. By making the corner angle equal to twice the tilt angle, the main lobes of each of the 4 sides point in the same direction and reinforce each other, increasing the gain.