1.
radio waves, electromagnetic waves
Electromagnetic radiation used for communication, broadcasting, and other technological applications.
電波を送る。
To send radio waves.
電波時計は正確だ。
Radio-controlled clocks are accurate.
電波時計 = radio-controlled clock
電波で情報を送信する。
Information is transmitted via radio waves.
テレビの電波を受信するためにアンテナが必要だ。
An antenna is needed to receive TV radio waves.
携帯電話の電波が人体に与える影響について研究が進んでいる。
Research is progressing on the effects of cell phone radio waves on the human body.
2.
signal, reception (informal)
In casual usage, refers to the quality of wireless signal reception.
ここは電波が悪い。
The reception is bad here.
山の中で電波が入らない。
There's no signal in the mountains.
電波が弱くて動画が見られない。
The signal is weak and I can't watch videos.
地下に入ると電波が届かなくなることがある。
When you go underground, the signal sometimes doesn't reach.
新しい基地局ができてから、この辺りは電波がよくなった。
Since the new base station was built, the signal in this area has improved.
TECHNICAL USE:
- 電波を発信する (to transmit radio waves)
- 電波を受信する (to receive radio waves)
- 電波障害 (radio interference)
- 電波法 (Radio Law)
EVERYDAY USE:
- 電波が悪い (poor signal/reception)
- 電波が入らない (no signal)
- 電波時計 (radio-controlled clock)
SLANG (dated): 電波系 was used to describe someone who seems disconnected from reality or has strange ideas (not recommended to use).
SCIENCE: 電波 is part of the electromagnetic spectrum, with frequencies lower than infrared.