Compact implies small in antenna size.

Bandwidth means the frequency range that antenna supports. A wide bandwidth means antenna covers broader frequency range, and vice versa.

Gain is an index indicating the reception level. It indicates the superiority or inferiority compared to the reference.

The three indices are deeply correlated and pose an inevitable rule. If the size of antenna has to be small while maintaining a wide bandwidth, the gain inevitably becomes lower.

Similarly,

• if the size of antenna has to be small while maintaining a high gain, the bandwidth inevitably becomes narrower.
• If broader bandwidth and high gain is necessary, the size of antenna becomes larger.

As such, it is considered impossible to design antennas with compact, wide bandwidth, and high-gain features all in one; however, as an automotive antenna supplier specialist, HARADA will strive to transcend such challenges.