Abstract: A low noise frequency synthesizer 10 that uses uses frequency dividers 13, 15, at least one of which(divider 15) is incrementable and decrementable in half integer steps, and analog gain compensation in a phase/frequency detector 14 to achieve lower noise, lower spurious levels and faster switching speed than traditional methods of frequency synthesis. The key features of the present invention are its half integer dividers 13, 15 and the ability to adjust the phase detector gain to compensate the loop for varying divide numbers. The synthesizer 10 comprises two dividers 13, 15 that provide two reference frequency signals that are a function of an input signal and an output signal of the synthesizer 10. A voltage controlled oscillator (VCO) 18 provides the output signal (f.sub.O) of the frequency synthesizer 10. A phase/frequency detector 14 compares the reference frequency signals and provides a phase error output signal that drives the VCO 18.

Abstract: A frequency synthesizer (100) for use in combination with the transmitter (30) for transmitting guidance information to one or more ground launched active radar guided missiles simultaneously which is tunable to a plurality of frequencies separated by a predetermined interval. The frequency synthesizer (100) employs a phase-locked loop (110) having a phase detector (114) which receives input signals of common frequency from two dividers (112 and 124). Frequency control is achieved by varying the divisor of one of the dividers (112).

Abstract: A frequency synthesizer (10) and method that achieves low phase noise and provides synthesized frequency signals in fine frequency step intervals. The synthesizer (10) comprises an L-band low phase noise frequency synthesizer with fine frequency step increments. The synthesizer (10) employs half-integer digital frequency dividing (25), VCO frequency offsetting, local oscillator harmonic mixing (34) and two phase locked loop circuits (12,13). The synthesizer (10) comprises a reference oscillator (11) for providing a reference frequency signal, and two phase locked loops (12,13). The first loop (12) is the fine loop and generates the frequency step size. The second loop (13) reduces the phase noise, reduces the frequency step size and translates to the desired freqeuncy. The output from a first VCO (21) is divided by a predetermined fixed number (31) to reduce the frequency step size and to reduce the phase noise.

Abstract: In a weapon system 10 incorporating a target position sensor (14), an information system (16), a power source (22), a launcher (20), and an airborne vehicle (18), a launcher control system (12) which incorporates a communications interface (26) for coupling the information system (16) and the target position sensor (14) to a launcher (20) and an airborne vehicle (18). The communications interface (26) receives target position information and launch and control orders and provides launcher and airborne vehicle status. A airborne vehicle interface (28) couples the launcher (20) and the airborne vehicle (18) to the information system (16) and a power source (22). A transmitter (30) communicates updated target position information to the airborne vehicle after launch. A power control unit (32) converts and regulates power from different power sources (22) to be used by the launcher control system (12).