Wide-band receiving apparatus with local oscillating circuit

A wide-band receiving apparatus, comprising:

• means for receiving a wide-band input signal containing modified RF signals of two or more different frequency bands and separating said RF signals by the bands;
• means for selecting one of said separated RF signals;
• a variable frequency local oscillating circuit for generating a first oscillating signal of a selected variable fundamental frequency;
• frequency converting means for converting the fundamental frequency of said first ocillating signal into at least one second oscillating signal of a frequency having a predetermined ratio to said selected variable fundamental frequency;
• a band-selector circuit for controlling the fundamental frequency of said oscillating signal based on a comparison of a frequency relating to the frequency of said second oscillating signal with a frequency relating to the frequency band of the selected RF signal;
• second selecting means for selecting one of said first oscillating signal and said at least one second oscillating signal based on the frequency band of said selected RF signal;
• means for changing a phase of said oscillating signal selected by said second selecting means thereby producing third and fourth oscillating signals having phases shifted 90 with respect to each other;
• a first mixer circuit for mixing said selected RF signal with said third oscillating signal to produce a first intermediate-frequency signal;
• a second mixer circuit for mixing said selected RF signal with said fourth oscillating signal to produce a second intermediate-frequency signal;
• means for composing said first and second intermediate-frequency signals together, with a phase difference of 90 between said first and second intermediate-frequency signals thereby generating a composed output;
• and
• a circuit for demodulating said composed output.