Question

You're engineering a new cell phone, and you'd like to incorporate the antenna enwrely within the phone, which is 9 cm long when closed. the antenna is to be a quarter-wavelength long-a common design for verwcally oriented antennas. if the cell-phone frequency is 2.4 ghz, will the antenna fit?

Answer 1

Wavelength = (speed) / (frequency)

= (3 x 10^8 m/s) / (2.4 x 10^9 Hz)

= 0.125 meter.

The quarter-wavelength antenna needs to be about 3 cm long. It fits fine inside the 9-cm case of the phone.