JPS62123835A - Transmitter-receiver - Google Patents

Abstract

PURPOSE:To prevent the gain reduction due to mis-matching by connecting an LC matching element an antenna and a transmitter-receiver input in the transmitter-receiver using different frequencies for the transmission/reception so as to match both the transmitter and receiver. CONSTITUTION:The inductance component of a loading coil 1a of a loading antenna 1 is adjusted at first and the resonance frequency of the antenna 1 itself is made coincident with the reception frequency of a receiver 3. In such a state, the capacitance of a capacitor C inserted between the antenna 1 and the transmitter 2 is adjusted and the transmitter 2 and the antenna 1 having a higher frequency than the reception frequency are matched. Thus, both the transmitter and the receiver are matched, than the gain reduction due to mis- matched antenna is prevented.

Description

[Detailed Description of the Invention] [Technical Field 1] The present invention relates to a transceiver that transmits and receives data at different frequencies using one loading antenna [Background Art] Conventionally, wireless intercoms and the like have been used as this type of transceiver. Since wireless intercoms are required to be smaller and lighter, it is desirable to use a single antenna for transmission and reception even when the transmitting and receiving frequencies of the transceivers 2 and 3 are different. An example of this is an antenna with the antenna base loaded.
There is a so-called loading antenna 1. However, when the transmission and reception frequencies are different, if the loading antenna 1 output is directly connected to the input/output terminals of the transmitter 2 and receiver 3 as shown in FIG. It is possible to match one antenna, but it is not possible to match the other, and there is a problem that the antenna gain of at least one of them becomes small, and in some cases, the gains of both may become small.

[Object of the Invention 1 The present invention has been made in view of the above points, and J, n
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The object of the present invention is to provide a transceiver that can be matched with a standard loading antenna.

[Disclosure of the Invention] (Embodiment) FIG. 1 is a diagram showing an embodiment of the present invention. In this embodiment, the lower frequency of the transmitter 2 and the receiver 3 is connected directly to the loading antenna 1. and the higher frequency one is connected to the loading antenna 1 via a capacitor C, which is a capacitive element.

A specific matching method for the transmitter 2 and receiver 3 will be described below. Here, the explanation will be given assuming that the following preconditions exist. First, let's assume that the transmitting frequency is f and the receiving frequency is 2.Then, let's assume that the transmitting frequency is set higher than the receiving frequency.In this case, the receiver 3 is directly connected to the loading antenna 1, and the transmitter 2 are connected via a capacitor C. As a matching method, first, the receiver 3 is matched, and then the transmitter 2 and loading antenna 1 are matched. Matching is performed by adjusting the inductance of the loading section 1a of the loading antenna 1 and varying the inductance of the loading section 1a so that the resonant frequency of the loading antenna 1 itself matches the reception frequency of the receiver 3. The loading antenna 1 adjusted as described above and the transmitter 2 are matched, but before that, the reason why the capacitor C is inserted between the transmitter 2 and the loading antenna 1 will be explained. When the loading antenna 1 and the transmitter 3 are matched, if you look at the loading antenna 1 from the high-frequency transmitter 2 side, the loading antenna 1 becomes inductive and is in a mismatched state. Matching between the transmitter 2 side and the loading antenna 1 is achieved by inserting a capacitor C between the transmitter 1 and the transmitter 2, and setting the loading antenna 1 to 311 g in the direction of capacitance when viewed from the transmitting side. Therefore, when matching the transmitter 2 and loading antenna 1, the receiver 3 side is in a state where it is matched with the loading antenna 1, so the inductance of the loading antenna 1 does not change. Adjustment is performed by varying only the capacitance of the capacitor C inserted between the loading antenna 1 and the transmitter 2.In this way, by varying the inductance of the loading section 1a of the loading antenna 1, the receiver 3 with a low frequency and loading antenna 1, and then a capacitor C inserted between loading antenna 1 and transmitter 2.
By varying the capacitance of 19 to match the high frequency transmitter 2 and the loading antenna 1, it is possible to match both the transmitter 2 and the receiver 3, and the gain of the transmitter 2 and receiver 3 is This allows for good transmission and reception without causing a drop in performance due to mismatching with the loading antenna 1.

[Effect of the Invention 1] As described above, the present invention adjusts the frequency of the lower frequency of the transmitter and the receiver to the loading antenna to match the lower frequency of the transmitter and the loading antenna. Since the higher frequency side is connected to the loading antenna via a capacitive element and the capacitance of the capacitive element is adjusted to match the higher frequency side with the loading antenna, both the transmitter and receiver can be matched. This has the effect that good transmission and reception can be performed without reducing the gain of the transmitter and receiver due to mismatch with the loading antenna.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram showing a conventional example. 1 is a loading antenna, 1a is a loading section, 2
is a transmitter, and 3 is a receiver.

Claims (1)

[Claims] (1) In a transceiver that transmits and receives at different frequencies using a single loading antenna loaded at the base of the antenna body, the transmitter and receiver with the lower frequency are directly connected to the loading antenna. Adjust the inductance of the lower frequency side to match the loading antenna, and connect the higher frequency side to the loading antenna via a capacitive element and adjust the capacitance of the capacitive element to match the lower frequency side with the loading antenna. A transmitter/receiver characterized in that the higher side of the antenna is matched with a loading antenna.