JPH0188538U - - Google Patents

Description

[Brief explanation of the drawing]

Figure 1 is a diagram of the principle of the present invention, Figure 2 is the antenna 2
3 is a timing chart of each part of the circuit in FIG. 2. FIG. 4 is a diagram showing an embodiment of the switching prohibition means in the case of four antennas. Figure 5 is a timing chart of each part of the circuit in Figure 4, Figure 6 is a diagram showing a pole antenna and a glass antenna for automobiles, and Figure 7A.
7B, and 8 are diagrams showing an embodiment of the connection detection means in the pole antenna, FIG. 9 is a diagram showing the outline of the glass antenna system, and FIG. 10 is the implementation of the antenna connection detection means in the glass antenna system. Figure 11 is a diagram showing an example of a conventional diversity receiver, and Figure 12 is a diagram showing a conventional diversity receiver.
FIG. 13 is a diagram showing the relationship between the antenna input signal strength and the output signal level of the M tuner, and FIG. 13 is a diagram showing the demodulated output when there is no signal under the conditions of FIG. 12 in a conventional diversity receiver. In the figure, 11, 12... Antenna, 13... Tuner, 14... Antenna connection circuit, 15... Holding means, 16... Quality determining means, 17... Switching control means,
21, 22...Antenna connection detection means, 23...Switching prohibition means.

Claims (1)

[Claims for Utility Model Registration] 1. A plurality of antennas 11 and 12, and a tuner 1 for extracting a received signal using radio waves received by one of the plurality of antennas 11 and 12.
3, having a plurality of connection ends that can be electrically connected to each of the plurality of antennas 11 and 12, and selecting one of the plurality of connection ends to electrically connect to the tuner 13; an antenna connection circuit 14 that realizes the condition, a quality determination means 16 that compares a value representing the quality of the received signal with a predetermined value and determines whether the received signal is good or bad, and a determination result of the quality determination means 16 that determines the quality of the received signal. A diversity receiver comprising a switching control means 17 for outputting a switching signal if the switching signal is not good, and a holding means 15 for outputting a selection signal to maintain the connection state if the switching signal is not outputted. A plurality of antenna connection detection means 21 detects whether the antenna is connected to each of the plurality of connection ends of the circuit 14 or is in a non-connection state and outputs the result as a connection signal. , 22 is provided between the switching control means 17 and the holding means 15, and when the switching control means 17 outputs a switching signal, if the connection end to be switched is in the connected state, the switching signal is transmitted to the holding means 15. A diversity receiver characterized in that it is provided with a switching inhibiting means 23 which transmits the switching signal to the terminal and does not transmit the switching signal if the switching signal is not connected. 2. The diversity receiver according to claim 1, wherein the antenna connection detection means 21 and 22 include a pair of light emitting elements and light receiving elements. 3 The antenna connection detection means 21 and 22 are equipped with a comparator that compares the voltage obtained by amplifying the signal received by the antennas 11 and 12 with a predetermined voltage. Receiving machine.