Patent ID: 8031790

Claim:
A radio communication apparatus which uses a low-intermediate frequency to transmit a multiband Orthogonal Frequency Division Multiplex (OFDM) signal for hopping a center frequency at a specified band interval, comprising: a sub-carrier power level compensator to compensate for an aperture effect of a digital-to-analog conversion by changing amplitudes of respective sub-carriers to provide compensated sub-carriers; an OFDM modulator to convert each compensated sub-carrier along a frequency axis into a signal along a time axis by performing a frequency to time domain conversion; a low-intermediate frequency multiplier to multiply a low-intermediate frequency and the signal along the time axis together to generate an OFDM-modulated low-intermediate frequency signal, the low-intermediate frequency being half a band interval for frequency hopping; a Digital-to-Analog (D/A) converter to convert the OFDM-modulated low-intermediate frequency signal into an analog signal using a specified sampling frequency; a frequency up-converter to up-convert the analog signal into a high-frequency transmission signal; and an intermediate frequency filter to remove unnecessary frequency components from the analog signal, the intermediate frequency filter including a Hilbert bandpass filter formed by two real filters having a same characteristic and interconnected by a gyrator, a predetermined absolute value being used for a half-band frequency of a ladder-type low-pass filter as a real filter, the predetermined absolute value also being used as a center frequency of said Hilbert bandpass filter, and an integer ratio being used for an element value of a ladder-type prototype filter.