What is an antenna?

Antennas receive and transmit radio waves.
We are constantly surrounded by various types of radio waves. Although we cannot see them, they are an indispensable part of our daily lives. As shown below, mobile phones and radios are representative devices that use radio waves.

What are radio waves?

Electricity and Magnetism

Radio waves embrace both electric and magnetic features. Region in space consisting of electricity are called electric fields while region in space consisting of magnetism are called magnetic fields.

What are radio waves?

Facts about Radio Waves

An important term associated to radio waves is frequency. Frequency is the number of waves repeated in one second, and is expressed with the unit - Hertz (Hz).

What are radio waves?

Reflection and Passing of Radio Waves

While radio waves generally propagate towards a single direction, they sometimes reflect as well. For example, radio waves are reflected on metal which has high electrical conductivity but pass through plastic which has high electrical resistivity.

What are radio waves?

Diffraction of Radio Waves

Aside from reflecting on and passing through objects, radio waves can work their way around obstacles such as buildings. This is called diffraction.

What happens when frequencies differ?

Characteristics of Different Frequency Bands

Depending on the frequency band (also called the frequency range), the way radio waves propagate and the amount of transmittable information differ. Generally, as shown below, the higher the frequency is, the easier it is for radios waves to propagate in a straight line and the larger the amount of transmittable information is. In contrast, the lower the frequency is, the easier it is for radio waves to diffract and the smaller the amount of transmittable information is.

What is required for automotive antennas?

Compact, Wide Bandwidth, High-Gain

Compact: Small in antenna size
Bandwidth: Frequency range that antenna supports
Gain: An index that indicates the reception level compared to the reference

Although it is extremely difficult to design antennas with compact, wide bandwidth and high-gain features all in one, as an automotive antenna supplier specialist, HARADA will strive to transcend such challenges.