Method and arrangement for frequency modulation of a high-frequency signal

• US 6,049,257 A
• Filed: 06/30/1998
• Issued: 04/11/2000
• Est. Priority Date: 01/13/1996
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Hauk, Joachim
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): Choe, Henry
• Application Number:
  US09/101,178
• Time in Patent Office: 651 Days
• Field of Search: 331/17, 331/25, 331/27, 332/100, 332/127, 332/128
• US Class Current: 332/127
• CPC Class Codes: G01S 13/345 using triangular modulation
• CPC Class Codes: G01S 7/35 Details of non-pulse systems
• CPC Class Codes: H03B 23/00 Generation of oscillations periodically swept over a predetermined frequency range angle-modulating circuits in general H03C3/00
• CPC Class Codes: H03C 3/0908 using a phase locked loop
• CPC Class Codes: H04L 27/12 Modulator circuits; Transmitter circuits

Abstract

In a method and an arrangement for frequency modulation of a high-frequency signal, where the high-frequency signal is generated with an oscillator which is controlled by comparison of an actual frequency signal with a variable set frequency signal, the actual frequency signal contains pulses with an average repetition frequency which corresponds to an actual frequency, with one pulse being derived from one edge of the high-frequency signal and its phase angle being determined by a predetermined clock pulse. The set frequency signal comprises pulses with an average repetition frequency which corresponds to a set frequency. The pulses increment or decrement an up/down counter from whose count a control voltage is derived for the oscillator.

Claims

1. A method for frequency modulating a high-frequency signal, comprising the steps of:

generating the high-frequency signal using an oscillator, the oscillator being regulated by comparing an actual frequency signal to a variable set frequency signal;

adjusting an up/down counter using at least one of;

a plurality of first pulses of the actual frequency signal and a plurality of second pulses of the variable set frequency signal; and

determining a control voltage for the oscillator using the up/down counter,

wherein the plurality of first pulses include an average repetition frequency corresponding to an actual frequency of the actual frequency signal,

wherein the plurality of second pulses include an average repetition frequency corresponding to a set frequency of the variable set frequency signal, and

wherein the up/down counter is adjusted in a first counting direction using the plurality of first pulses, and wherein the up/down counter is adjusted in a second counting direction using the plurality of second pulses, the second counting direction being opposite to the first counting direction.

2. The method according to claim 1, further comprising the steps of:

determining the plurality of first pulses using at least one edge of the high-frequency signal; and

determining a phase angle of the plurality of first pulses using a predetermined clock pulse.

3. The method according to claim 1, further comprising the steps of:

before the actual frequency signal is determined, mixing the high-frequency signal with a signal of a high-precision reference oscillator to determine a mixed signal; and

determining the actual frequency signal using the mixed signal.

4. The method according to claim 1, further comprising the step of:

before formation of the actual frequency signal, subjecting the high-frequency signal to a frequency division.

5. The method according to claim 1, further comprising the step of:

providing a current to a capacitor in one of a first direction and a second direction as a function of a sign of the up/down counter to determine the control voltage, wherein the first direction is opposite to the second direction.

6. The method according to claim 2, further comprising the steps of:

adding a variable number to a content value of an accumulator in the predetermined clock pulse to determine the set frequency signal; and

when a most significant bit of the content value jumps to a predetermined binary value, outputting a pulse of the plurality of second pulses.

7. The method according to claim 6, further comprising the steps of:

storing the variable number in a further up/down counter; and

adjusting the variable number by adjusting the up/down counter as a function of at least one modulation signal.

8. The method according to claim 7, further comprising the steps of:

setting the further up/down counter to a starting value;

repeatedly adding the starting value to a corresponding content value of the accumulator; and

determining the actual frequency signal corresponding to a non-frequency-modulated signal using the starting value.

9. The method according to claim 7, further comprising the step of:

providing at least one binary signal causing one of a linear increase and a linear decrease in frequency to a first input of the further up/down counter and a second input of the further up/down counter.

10. The method according to claim 9, further comprising the step of:

reducing a slope of the one of the linear increase and the linear decrease using the at least one binary signal being interrupted during a portion of a plurality of clock pulse periods.

11. The method according to claim 10, wherein the at least one binary signal is provided only during every second clock pulse of the plurality of clock pulse periods, and further comprising the step of reducing the slope by a half.

12. An arrangement for a frequency modulation of a high-frequency signal, comprising:

an oscillator generating the high-frequency signal;

a first arrangement determining an actual frequency signal using the high-frequency signal;

a generator generating a variable set frequency signal;

an up/down counter including a counter value; and

a second arrangement determining a control voltage for the oscillator using the counter value, the second arrangement coupled to the up/down counter,

wherein the actual frequency signal includes a plurality of first pulses having an average repetition frequency corresponding to an actual frequency of the actual frequency signal, the actual frequency signal being transmitted to a first counter input of the up/down counter,

wherein the set frequency signal includes a plurality of second pulses having an average repetition frequency corresponding to a set frequency of the variable set frequency signal, the set frequency signal being transmitted to a second counter input of the up/down counter and

wherein the plurality of first pulses adjust the up/down counter in a first counter direction, and the plurality of second pulses adjust the up/down counter in a second counter direction, the first counter direction being opposite to the second counter direction.

13. The arrangement according to claim 12,

wherein the second arrangement includes a first current source, a second current source and a capacitor,

wherein the first current source supplies a current to the capacitor in a first current direction, the second current source supplies the current to the capacitor in a second current direction, and the first current direction is opposite to the second current direction and

wherein one of the first current source and the second current source is switched into a circuit as a function of a sign of the counter value.

14. The arrangement according to 12, further comprising:

a further up/down counter including a further counter value,

wherein the generator includes an accumulator having a content value, the content value being added to the further counter value at a predetermined clock rate, and the further counter value being adjusted as a function of at least one modulation signal in a predetermined clock pulse.