Apply the maximum entropy method for signal obtained by transmission and reception of electromagnetic waves to a subject, by determining the frequency of the peak component to be measured, it is possible to obtain the desired information while avoiding the influence of noise and appropriate condition of the subject It is the peak frequency of the signal measurement system for the evaluable. From the phase difference signal containing the noise peaks other than the component to be measured obtained by the 11 electromagnetic wave transmitting and receiving means, the signal analyzing unit 12, applying the maximum entropy method as target signal portions of the analysis duration short predetermined phase difference signal to obtain the frequency to run the spectral estimate was represents the frequency of the peak component, the same process is repeated while moving the analyzed position of the analysis time width of a time axis of the phase difference signal, to derive continuous frequency Since, it is possible to understand the changes over time of the frequency of the peak component, can be suitably evaluated in a short period of time led to a change of state of the peak component of the measured phase difference signal. [Selection] Figure Figure 1被験体に対する電磁波の送受信で得られた信号に対し最大エントロピー法を適用し、測定対象のピーク成分の周波数を求めて、ノイズの影響を避けて所望の情報を取得でき、被験体の状態を適切に評価可能とする信号のピーク周波数測定システムである。電磁波送受信手段11によって得られた測定対象のピーク成分以外のノイズも含む位相差信号から、信号解析手段12が、位相差信号の所定の短い解析時間幅の信号部分を対象として最大エントロピー法を適用したスペクトル推定を実行し、ピーク成分の発生頻度を表す周波数を求め、さらに位相差信号の時間軸上で解析時間幅分の解析対象位置を動かしながら同様の処理を繰返し、周波数を継続的に導くことから、ピーク成分の周波数の時間経過に伴う推移を把握でき、位相差信号における測定対象のピーク成分の変化の状態を短時間に導出して適切に評価できる。【選択図】図1
