| 摘要 |
PROBLEM TO BE SOLVED: To provide an angle arithmetic circuit capable of performing an angle operation with a simple configuration. SOLUTION: This circuit consists of code discriminating devices 101 and 102, a decoder 103, a tangent arithmetic circuit 105, comparators 107, 108, 115, 116, 117 and 118 and decoders 109 and 119. Tangent signals Itan1, Itan2, IItan1 and IItan2 obtained by multiplying a common-mode signal I by a phase tangent being reference such as tan 22.5 deg. (=45 deg./2) are calculated by using a shift register 110, adders 111 and 112 and inverters 106, 113 and 114. It is possible to realize an angle operation with a simple configuration without using a ROM because the angle operation is performed with a pitch being below a 90 deg. two-dimensional vector consisting of the common-mode signal I and an orthogonal signal Q according to comparison results of the tangent signals with the signal Q.
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