Abstract: It is possible to generate D/A conversion voltage in which an error generated by numeric irregularities of a D/A conversion element such as resistor constituting a D/A converter 11 is corrected. A waveform generation method characterized in that input data into a D/A converter 11 are provided to the D/A converter in order at a timing at which a voltage of a desired waveform which has D/A conversion data indicating a conversion amount of the input data obtained by varying the input data by a minimum conversion unit or a unit obtained by multiplying the minimum conversion unit by an integer, and which varies with time series, becomes substantially equal to a D/A-converted voltage, whereby the D/A-converted voltage is generated in accordance with the desired waveform.

Abstract: It is possible to generate D/A conversion voltage in which an error generated by numeric irregularities of a D/A conversion element such as resistor constituting a D/A converter 11 is corrected. A waveform generation method characterized in that input data into a D/A converter 11 are provided to the D/A converter in order at a timing at which a voltage of a desired waveform which has D/A conversion data indicating a conversion amount of the input data obtained by varying the input data by a minimum conversion unit or a unit obtained by multiplying the minimum conversion unit by an integer, and which varies with time series, becomes substantially equal to a D/A-converted voltage, whereby the D/A-converted voltage is generated in accordance with the desired waveform.

Abstract: It is possible to generate D/A conversion voltage in which an error generated by numeric irregularities of a D/A conversion element such as resistor constituting a D/A converter 11 is corrected. A waveform generation method characterized in that input data into a D/A converter 11 are provided to the D/A converter in order at a timing at which a voltage of a desired waveform which has D/A conversion data indicating a conversion amount of the input data obtained by varying the input data by a minimum conversion unit or a unit obtained by multiplying the minimum conversion unit by an integer, and which varies with time series, becomes substantially equal to a D/A-converted voltage, whereby the D/A-converted voltage is generated in accordance with the desired waveform.

Abstract: It is possible to generate D/A conversion voltage in which an error generated by numeric irregularities of a D/A conversion element such as resistor constituting a D/A converter 11 is corrected. A waveform generation method characterized in that input data into a D/A converter 11 are provided to the D/A converter in order at a timing at which a voltage of a desired waveform which has D/A conversion data indicating a conversion amount of the input data obtained by varying the input data by a minimum conversion unit or a unit obtained by multiplying the minimum conversion unit by an integer, and which varies with time series, becomes substantially equal to a D/A-converted voltage, whereby the D/A-converted voltage is generated in accordance with the desired waveform.

Abstract: A conventional waveform generation circuit was required to increase a number of bits or a sampling rate for a D/A converter to enhance a precision of waveform shaping, and had a problem that a cost was increased. Therefore, as a method for enhancing the precision of waveform shaping, a quantization error of an output waveform is made smaller by controlling an output time interval of an output value from a D/A converter so as to make a difference in an output voltage between target waveform and output waveform smaller. As a result, even if the D/A converter has a small number of bits, the waveform can be generated at high precision. Also, this waveform generation method may be applied to modulation control of a radar apparatus, as a result, constituting a small and inexpensive modulation circuit for an oscillator.

Abstract: A conventional waveform generation circuit was required to increase a number of bits or a sampling rate for a D/A converter to enhance a precision of waveform shaping, and had a problem that a cost was increased. Therefore, as a method for enhancing the precision of waveform shaping, a quantization error of an output waveform is made smaller by controlling an output time interval of an output value from a D/A converter so as to make a difference in an output voltage between target waveform and output waveform smaller. As a result, even if the D/A converter has a small number of bits, the waveform can be generated at high precision. Also, this waveform generation method may be applied to modulation control of a radar apparatus, as a result, constituting a small and inexpensive modulation circuit for an oscillator.

Abstract: A multiple-beam antenna system capable of forming a plurality of beams at one time in different directions. The antenna system has a plurality of element antennas arranged in a predetermined configuration. A signal received by each element antenna is converted to a digital signal which in turn is subjected to a Fourier transform. The Fourier-transformed receiving signal is multiplied with a Fourier-transformed weighting function. The resultant product is subjected to an inverse Fourier transform to be used for calculating an antenna radiation pattern. A holographic multiple-beam antenna is also disclosed.