| 摘要 |
1. Frequency syntheziser for a TACAN system comprising a voltage controlled oscillator (1), a frequency divider (2) having a fixed division rate and having its input connected to the output of the voltage controlled oscillator (1), a frequency divider with variable division rate v, the input of which is connected to the output of the frequency divider (2) having a fixed rate, a control unit (7) which is able to control the variable rate divider (3) via a control signal correction device (8), a phase comparator (4), one input of which is connected to the output of the variable rate divider, a reference oscillator (5), the output of which is connected to the other input of the phase comparator, the output of the latter being connected via a low pass filter (6), to the control input of the voltage controlled oscillator (1), characterized in that the voltage controlled oscillator (1) directly furnishes the TACAN frequency (F), that the control unit (7) furnishes a first signal (S) constituted by a binary digit which indicates the type of equipment (earth or bord) in which the indicator which is identical for both equipments is mounted, a second signal (M) constituted by a binary digit indicating the selected operation mode (X or Y) and two signals (U and D) for selecting one channel out of 125 channels, constituted by a first number having four binary digits (U1, U2, U3, U4) giving the units digits, and a second number having four binary digits (D1, D2, D3, D4) giving the decimal digit, that the fixed rate r is equal to 8, that the reference frequency (f) is equal to 125 kilo-cyles per second, that the variable rate v is included between 962 and 1213 and that the correction device (8) is able to add to the two selection signals (U and D) corrections signals representing in binary notation a number which is equal to - 07 if the first (S) and the second signal (M) indicate that the syntheziser is mounted in an earth equipment utilized in the low band, - 133 if the first (S) and the second signal (M) indicate that the syntheziser is mounted in an earth equipment and utilized in the high band ; - 70 if the first (S) and the second signal (M) indicate that the syntheziser is mounted in an equipment on bord. |
