Receiving circuit for multi-slot receiving provided with circuit for adjusting frequency characteristic of active filter

1. A receiver circuit comprising:

an active filter circuit including an active filter which filters an inputted transmission signal using a predetermined frequency characteristic, and an adjusting circuit which adjusts the frequency characteristics of said active filter;

a receiving device including a demodulator which demodulates the filtered transmission signal; and

a control device which controls a power source of said receiving device using a first power source control signal, and controls a power source of said active filter circuit using a second power source control signal,

wherein said control device controls the power source of said receiving device using the first power source control signal, upon reception of data including a plurality of reception slots having a guard bit provided between reception slots adjacent to each other, the first power source control signal becoming a power source ON signal before starting of reception of the data, the first power source control signal becoming a power source ON signal after temporarily becoming a power source OFF signal within the guard bit, and the first power source control signal becoming a power source OFF signal after completing the reception of the data, and

wherein said control device also controls the power source of said active filter circuit using the second power source control signal, the second power source control signal becoming a power source ON signal before starting of the reception of the data, and thereafter, maintaining the power source ON signal as an ON signal until the second power source control signal becomes a power source OFF signal after completing the reception of the data.

2. The receiver circuit as claimed in claim 1 , wherein said control device generates and outputs the power source OFF signal of the second power source control signal after a lapse of a predetermined delay interval from the power source OFF signal of the first power source control signal on the basis of the inputted first power source control signal.

3. The receiver circuit as claimed in claim 1 , wherein said control device comprises:

a generator device which generates a reference signal having a predetermined reference frequency; and

a frequency-dividing device which generates and outputs a frequency-divided signal showing a delay interval by dividing the frequency of the reference signal by a predetermined frequency-divided number.

4. The receiver circuit as claimed in claim 2 , wherein said control device comprises:

a generator device which generates a reference signal having a predetermined reference frequency; and

a frequency-dividing device which generates and outputs a frequency-divided signal showing the delay interval by dividing the frequency of the reference signal by a predetermined frequency-divided number.

5. The receiver circuit as claimed in claim 1 , wherein said control device is configured to be able to change a delay interval.

6. The receiver circuit as claimed in claim 3 , wherein said control device is configured to be able to change the delay interval.

7. The receiver circuit as claimed in claim 1 , wherein said control device comprises:

a timer circuit which counts a time of a delay interval; and

a logic circuit which generates and outputs the power source OFF signal of the second power source control signal after a lapse of a counted delay interval from the power source OFF signal of the first power source control signal.

8. The receiver circuit as claimed in claim 3 , wherein said control device comprises:

a timer circuit which counts a time of the delay interval; and

a logic circuit for generating and outputting the power source OFF signal of the second power source control signal after a lapse of a counted delay interval from the power source OFF signal of the first power source control signal.

9. The receiver circuit as claimed in claim 7 , wherein said timer circuit includes a counter circuit.

10. The receiver circuit as claimed in claim 8 , wherein said timer circuit includes a counter circuit.

11. The receiver circuit as claimed in claim 7 , wherein said timer circuit includes a charge and discharge circuit.

12. The receiver circuit as claimed in claim 8 , wherein said timer circuit includes a charge and discharge circuit.

13. A transceiver circuit comprising:

a transmitter circuit which transmits a transmission signal; and

a receiver circuit which receives the transmission signal,

wherein said receiver circuit comprises:

an active filter circuit including an active filter which filters an inputted transmission signal using a predetermined frequency characteristic, and an adjusting circuit which adjusts the frequency characteristic of said active filter; and

a receiving device including a demodulator which demodulates the filtered transmission signal,

wherein said receiver circuit comprises a control device which controls a power source of said receiving device using a first power source control signal, and controls a power source of said active filter circuit using a second power source control signal, and

wherein said control device controls the power source of said receiving device using the first power source control signal, upon reception of data including a plurality of reception slots having a guard bit provided between reception slots adjacent to each other, the first power source control signal becoming a power source ON signal before starting of reception of the data, the first power source control signal becoming a power source ON signal after temporarily becoming a power source OFF signal within the guard bit, and the first power source control signal becoming a power source OFF signal after completing the reception of the data, and

wherein said control device also controls the power source of said active filter circuit using the second power source control signal, the second power source control signal becoming a power source ON signal before starting of the reception of the data, and thereafter, maintaining the power source ON signal as an ON signal until the second power source control signal becomes a power source OFF signal after completing the reception of the data.

14. A communication apparatus comprising:

a transceiver circuit including a transmitter circuit which transmits a transmission signal; and

a receiver circuit which receives the transmission signal,

wherein said receiver circuit comprises:

an active filter circuit including an active filter which filters an inputted transmission signal using a predetermined frequency characteristic, and an adjusting circuit which adjusts the frequency characteristic of said active filter; and

a receiving device including a demodulator which demodulates the filtered transmission signal,

wherein said receiver circuit comprises a control device which controls a power source of said receiving device using a first power source control signal, and controls a power source of said active filter circuit using a second power source control signal, and

wherein said control device controls the power source of said receiving device using the first power source control signal, upon reception of data including a plurality of reception slots having a guard bit provided between reception slots adjacent to each other, the first power source control signal becoming a power source ON signal before starting of reception of the data, the first power source control signal becoming a power source ON signal after temporarily becoming a power source OFF signal within the guard bit, and the first power source control signal becoming a power source OFF signal after completing the reception of the data, and

wherein said control device also controls the power source of said active filter circuit using the second power source control signal, the second power source control signal becoming a power source ON signal before starting of the reception of the data, and thereafter, maintaining the power source ON signal as an ON signal until the second power source control signal becomes a power source OFF signal after completing the reception of the data.

15. A receiver circuit comprising:

a front-end circuit which amplifies or frequency-converts an inputted transmission signal;

an active filter circuit including an active filter which filters the amplified or frequency-converted transmission signal using a predetermined frequency characteristic, and an adjusting circuit which adjusts the frequency characteristic of said active filter;

a demodulator demodulating the filtered transmission signal; and

a control device which controls a power source of said front-end circuit and a power source of said demodulator using a first power source control signal, and which controls a power source of said active filter circuit using a second power source control signal,

wherein said control device controls the power source of said front-end circuit using the first power source control signal, upon reception of data including a plurality of reception slots having a guard bit provided between reception slots adjacent to each other, the first power source control signal becoming a power source ON signal before starting of reception of the data, the first power source control signal becoming a power source ON signal after temporarily becoming a power source OFF signal within the guard bit, and the first power source control signal becoming a power source OFF signal after completing the reception of the data, and

wherein said control device also controls the power source of said active filter circuit using the second power source control signal, the second power source control signal becoming a power source ON signal before starting of the reception of the data, and thereafter, maintaining the power source ON signal as an ON signal until the second power source control signal becomes a power source OFF signal after completing the reception of the data.