Frequency hopping communication device with simple structure

A method for restricting frequency deviation of a transmission signal transmitted from a frequency hopping communication device within a predetermined range regardless of hopping frequencies, said frequency hopping communication device including a voltage controlled oscillator for producing a modulated signal that a carrier wave is modulated by a modulation signal, said carrier wave having a carrier frequency changed into any one of hopping frequencies at regular intervals, said method comprising the steps of:

• memorizing a plurality of modulation coefficients related to the hopping frequencies;
• reading out one of the modulation coefficients as a read out modulation coefficient on the basis of a following hopping frequency from said memory when the following hopping frequency is decided;
• and
• adjusting voltage amplitude of the modulation signal by the use of the read out modulation coefficient to restrict frequency deviation of the modulated signal within a predetermined range regardless of the carrier frequency.

A method for finding modulation coefficients related to hopping frequencies, said modulation coefficients used for restricting frequency deviation of a transmission signal transmitted from a frequency hopping communication device within a predetermined range regardless of a carrier frequency, said frequency hopping communication device including a voltage controlled oscillator for producing a modulated signal that a carrier wave with the carrier frequency is modulated by a modulation signal, the carrier frequency changed into any one of hopping frequencies at regular intervals, said method comprising the steps of:

• connecting a measuring computer and a frequency deviation measuring unit with said frequency hopping communication device;
• directing, from said computer, said frequency hopping communication device to maintain one of the hopping frequencies as a first carrier frequency;
• transmitting, from said frequency hopping communication device to said frequency deviation measuring unit, a first transmission signal that the first carrier frequency is modulated by the use of a predetermined pattern signal;
• measuring, at said frequency deviation measuring unit, frequency deviation of the first transmission signal to obtain a first result;
• directing, from said computer, said frequency hopping communication device to maintain another one of the hopping frequencies as a second carrier frequency;
• transmitting, from said frequency hopping communication device to said frequency deviation measuring unit, a second transmission signal that the second carrier frequency is modulated by the use of the predetermined pattern signal;
• measuring, at said frequency deviation measuring unit, frequency deviation of the second transmission signal to obtain a second result;
• and
• calculating the modulation coefficients by the use of linear interpolation using the first carrier frequency, the first result, the second carrier frequency and the second result.