Frequency modulated radio frequency broadcast network employing a synchronous frequency modulated booster system

A synchronous frequency modulated booster for re-transmitting a frequency modulated broadcast signal comprising:

• A. transmitting means for re-transmitting a frequency modulated broadcast signal;
• B. receiving means for receiving a frequency modulated intermediate frequency signal;
• and
• C. a synchronous frequency modulated exciter receiving said frequency modulated intermediate frequency signal from said receiving means and applying to said transmitting means a frequency modulated broadcast signal for re-transmission by said transmitter means,
• D. said synchronous frequency modulated exciter comprising:
• (a) means responsive to said receiving means for producing a frequency reference signal representative of the frequency modulated intermediate frequency signal,
• (b) a first phase locked loop circuit responsive to said receiving means for producing a first stable phase locked frequency signal representative of the frequency modulated intermediate frequency signal,
• (c) a second phase locked loop circuit including a first voltage controlled oscillator, said first voltage controlled oscillator generating the frequency modulated broadcast signal, said first voltage controlled oscillator being phase locked to said frequency reference signal produced by said means, and
• (d) correcting phase locked loop circuit means responsive to the output of said first voltage controlled oscillator and responsive to said stable phase locked frequency produced by said first phase locked loop circuit and connected to said second phase locked loop circuit for correcting phase differences between the output of said first voltage controlled oscillator and said frequency reference signal produced by said means,
• (e) said second phase locked loop circuit including a first mixer circuit, one input of said first mixer circuit being connected to the output of said first voltage controlled oscillator, said correcting phase locked loop circuit means including a second voltage controlled oscillator, said second voltage controlled oscillator being connected to another input of said first mixer circuit producing a signal for correcting phase differences between the output of said first voltage controlled oscillator and said frequency reference signal produced by said means.

A synchronous frequency modulated booster for re-transmitting a frequency modulated broadcast signal comprising:

• A. transmitting means for re-transmitting a frequency modulated broadcast signal;
• B. receiving means for receiving a frequency modulated intermediate frequency signal;
• and
• C. a synchronous frequency modulated exciter receiving said frequency modulated intermediate frequency signal from said receiving means and applying to said transmitting means a frequency modulated broadcast signal for re-transmission by said transmitter means,
• D. said synchronous frequency modulated exciter comprising:
• (a) first means responsive to said receiving means for producing a frequency reference signal representative of the frequency modulated intermediate frequency signal,
• (b) a phase locked loop circuit including a voltage controlled oscillator, said voltage controlled oscillator generating the frequency modulated broadcast signal, said voltage controlled oscillator being phase locked to said frequency reference signal produced by said first means, and
• (c) second means including a phase error correcting circuit connected to the output of said voltage controlled oscillator and said phase locked loop circuit and responsive to said receiving means for correcting phase differences between the output of said voltage controlled oscillator and said frequency reference signal produced by said first means.