NMR measurement apparatus

A Nuclear Magnetic Resonance (NMR) measurement apparatus comprising:

• a mixer configured to multiply a transmission signal having a plurality of different frequency components by a local signal to generate a frequency-converted transmission signal under a condition for frequency conversion;
• a power amplifier configured to amplify the frequency-converted transmission signal and output an amplified transmission signal;
• a demultiplexing circuit including a plurality of filters arranged in parallel with each other, each filter of the plurality of filters having a different frequency characteristic, wherein the plurality of filters is configured to enable the amplified transmission signal to pass simultaneously in parallel through the plurality of filters to generate a plurality of transmission signals corresponding to a plurality of different irradiation frequencies, each of the plurality of transmission signals including a different component of respective irradiation frequencies of the plurality of different irradiation frequencies, and configured to output the plurality of transmission signals to an NMR detection circuit;
• and
• a controller configured to set the condition for frequency conversion, wherein the condition for frequency conversion is a condition for generating the plurality of different irradiation frequencies,
• wherein the plurality of transmission signals comprise a first transmission signal having a first irradiation frequency and a second transmission signal having a second irradiation frequency,
• wherein one of the first irradiation frequency and the second irradiation frequency is a primary reference frequency and another of the first irradiation frequency and the second irradiation frequency is a sub reference frequency,
• wherein a difference method or a summation method is employed as a frequency conversion method for the frequency conversion by the mixer,
• wherein the plurality of different frequency components of the transmission signal comprise a first frequency component having a first frequency and a second frequency component having a second frequency,
• wherein the condition for frequency conversion comprises the first frequency and the second frequency,
• wherein a frequency, among the first frequency and the second frequency, which corresponds to the primary reference frequency, is a designated frequency that is designated within a range of frequencies which the NMR measurement apparatus is configured to generate as an intermediate frequency,
• wherein a frequency, among the first frequency and the second frequency, which corresponds to the sub reference frequency, is a calculated frequency that is calculated within the range of frequencies,
• wherein the frequency of the local signal is calculated based on the primary reference frequency, the designated frequency, and the frequency conversion method,
• wherein the calculated frequency is calculated based on the sub reference frequency, the frequency of the local signal, and the frequency conversion method, and
• wherein the designated frequency is designated, such that the calculated frequency is not a negative frequency and does not exceed an upper limit of the range of frequencies.