Switching circuits to calculate transmission and reception circuit delays in a distance measuring device

A distance measuring device comprising:

• a transmission circuit configured to transmit a signal for distance measurement;
• a reception circuit configured to receive the signal for distance measurement;
• a first switching circuit configured to switch a route between the transmission circuit and an antenna and a route between the reception circuit and the antenna;
• an impedance adjustable circuit adjusted to have a higher impedance than an impedance of the antenna;
• a second switching circuit configured to switch conduction and non-conduction between the impedance adjustable circuit and the transmission circuit;
• a third switching circuit configured to switch conduction and non-conduction between the impedance adjustable circuit and the reception circuit;
• and
• a fourth switching circuit configured to switch conduction and non-conduction between the impedance adjustable circuit and the second switching circuit and conduction and non-conduction between the impedance adjustable circuit and the third switching circuit,
• wherein at least one of a filter configured to restrict the signal for distance measurement transmitted from the transmission circuit and a signal for distance measurement received by the antenna within a desired frequency band, a first amplifier configured to amplify the signal for distance measurement, and a second amplifier configured to amplify the signal for distance measurement is not included.