JPH09148961A - Radio transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge the excitation power of an antenna and to improve intra- oscillation loop efficiency by using the antenna instead of a matching coil of an oscillator. SOLUTION: The coil of a conventional Colpitts oscillation circuit is substituted for the antenna ANT1 and an oscillation circuit 10 is constituted. Thus, power voltage Vcc is impressed and oscillation is started with the amplification function of a transistor Tr and the resonance frequency peculiar to the oscillator Re. Oscillation high frequency current is allowed to flow through ANT1 of the oscillation loop and the ANT1 radiates a radio wave. Since the ANT1 is arranged at the post-stage of the oscillator Re, a harmonic component except for the basic wave of the radio wave which the ANT1 radiates can be suppressed with the filter effect of the oscillator Re. The oscillation power of the oscillation loop is consumed with the radio resistance of ANT1 and the loss of the other oscillation loop circuit element becomes small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device, a remote controller, a wireless LAN (LAN), a wireless transmitter used for keyless entry and the like.

[0002]

2. Description of the Related Art A Colpitts type oscillation circuit is shown in FIG. 10 as an example of an oscillation circuit of a conventional radio transmitter of this type. The collector of the transistor Tr is connected to the power supply voltage Vcc and is also connected to the ground via the series circuit of the bias resistors R1 and R2. The base is connected to the ground through the series circuit of the capacitors C1 and C2, and is also connected to the ground through the connection point between the resistors R1 and R2, the matching coil L1 and the oscillator Re. The emitter of the transistor Tr is connected to the connection point between the capacitors C1 and C2 and the resistor R
3 is connected to the ground. Further, the collector of the transistor Tr is connected to the ground via the capacitor C3 and the antenna ANT. And
A part of the energy of the oscillation frequency created by the oscillation loop of the oscillator Re and the transistor Tr is radiated as a radio wave from the antenna ANT connected to the collector side of the transistor Tr. FIG. 11 shows a feedback oscillator circuit as another example of the oscillator circuit of the conventional radio transmitter. The amplifier A and the filter-type oscillator Re form an oscillation loop, and the matching coil L is provided from both sides of the filter-type oscillator Re.
2 and L3 are respectively connected to the ground. Also,
The antenna ANT is connected to the ground through the capacitor C3 at the output end of the amplifier A. Then, a part of the oscillation energy created by the oscillation loop of the filter oscillator Re and the amplifier A is radiated as a radio wave from the antenna ANT.

[0003]

However, the conventional oscillation circuit of the radio transmitter is the Colpitts type oscillation circuit shown in FIG. 10 and the feedback type oscillation circuit shown in FIG.
Since a part of the oscillation energy accumulated in the oscillation loop is radiated from the antenna connected outside the oscillation loop, the total power of the oscillation energy cannot be radiated as a radio wave from the antenna, and the antenna radiation efficiency is poor.

Therefore, according to the present invention, an antenna is provided outside the loop by using the antenna instead of the conventional antenna type connected to the outside of the oscillation loop instead of the matching coil of the oscillator in the oscillation loop. The power to excite the antenna is increased and the transmission output can be increased,
At the same time, the efficiency in the oscillation loop is also improved, resulting in low power consumption
Moreover, it is an object of the present invention to provide a small-sized wireless transmission device having a simple oscillator circuit configuration.

[0005]

The present invention is characterized by adopting the following means in order to achieve the above object. 1. A radio transmission device, wherein an electric wave is transmitted by connecting an antenna instead of a matching circuit coil of an oscillator in an oscillation circuit.

[0006] 2. 2. The wireless transmission device according to 1 above, wherein the antenna is connected to at least one of a front stage and a rear stage of the oscillator in series or in parallel with the oscillator.

[0007] 3. 2. The wireless transmission device according to claim 1, wherein the antenna is connected in series and in parallel with the oscillator to at least one of a front stage and a rear stage of the oscillator.

4. The wireless transmission device according to any one of 1 to 3 above, wherein when the number of the antennas is 2, these antennas have different directional characteristics.

[0009] 5. 5. The wireless transmission device according to any one of 1 to 4 above, wherein a phase adjusting capacitor, a coil, or a resistor is connected to the antenna in series or in parallel.

[0010] 6. 6. The wireless transmission device according to any one of 1 to 5 above, wherein the oscillation circuit includes a Colpitts oscillation circuit, a negative resistance oscillation circuit, and a feedback oscillation circuit.

As described above, according to the present invention, since the antenna is used in place of the matching coil of the oscillator in the oscillator circuit, the power for exciting the antenna is larger and the transmission output is increased than when the antenna is provided outside the loop. In addition, the efficiency in the oscillation loop is also improved. That is, as compared with the case where the oscillation power of the oscillation circuit is taken out of the oscillation loop and transmitted, by transmitting from the oscillation loop, it is possible to suppress the decrease in the oscillation energy of the oscillation loop and reduce the energy for maintaining the oscillation. it can. Therefore, power consumption of the oscillator circuit can be reduced.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an oscillation circuit of a first embodiment of a wireless transmission device of the present invention will be described with reference to FIG. As the oscillator circuit 10 of this embodiment, a Colpitts oscillator circuit similar to the conventional example shown in FIG. 10 is used. The collector of the transistor Tr is connected to the power supply voltage Vcc and is also connected to the ground via the series circuit of the bias resistors R1 and R2. The base of the transistor Tr is connected to the ground through the series circuit of the capacitors C1 and C2, and is also connected to the ground through the connection point of the resistors R1 and R2, the series circuit of the antenna ANT1 and the oscillator Re. Therefore, the antenna ANT1
Is connected to the latter stage of the oscillator Re. The emitter of the transistor Tr is connected to the connection point between the capacitors C1 and C2, and is also connected to the ground via the resistor R3.

In the oscillation circuit 10 of this embodiment, the coil L1 of the Colpitts type oscillation circuit in the conventional example shown in FIG. 10 is replaced with an antenna ANT1 and an antenna A and a capacitor C3 connected to the collector of the transistor Tr.
It has a structure in which NT is removed.

The oscillating circuit 10 of this embodiment comprises a base of a transistor Tr, an emitter, an oscillator Re and an antenna A.
An oscillation loop is formed by the closed circuit of NT1. The oscillator Re is composed of a SAW oscillator, a crystal oscillator, a lithium tantalate oscillator, a lithium niobate oscillator, or the like.

As described above, the oscillator circuit 10 of this embodiment has the antenna AN in the oscillation loop of the Colpitts oscillator circuit.
It has a circuit configuration in which T1 is arranged. Therefore, simultaneously with the application of the power supply voltage Vcc, oscillation is started with the amplification function of the transistor Tr and the unique resonance frequency of the oscillator Re, and a high frequency current of oscillation flows through the antenna ANT1 arranged in the oscillation loop. High frequency current is applied to antenna A
Radio waves are emitted from NT1. Since the antenna ANT1 is connected to the latter stage of the oscillator Re,
Due to the filter effect of the oscillator Re, harmonic components other than the fundamental wave of the radio wave radiated from the antenna ANT1 are suppressed. Further, the oscillation power of the oscillation loop is consumed by the radiation resistance of the antenna ANT1, and the loss of the circuit elements of other oscillation loops is reduced.

Next, an oscillator circuit of a second embodiment of the wireless transmitter of the present invention will be described with reference to FIG. The oscillator circuit 20 of the present embodiment is different from the oscillator circuit 10 of the first embodiment shown in FIG. 1 in that an antenna ANT2 is connected in front of the oscillator Re instead of the matching coil. Others are the same as those in FIG. 1, so the same reference numerals as those in FIG.

In addition to the function and function of the oscillator circuit 10 of the first embodiment, the oscillator circuit 20 of the present embodiment has two antennas ANT1 and ANT2. Therefore, by changing the directions of these antennas, It is possible to flatten the directional characteristic by eliminating the null point of the radiation pattern of the antenna. That is, the directional characteristic is flattened by adjusting the angle of the null point of the radiation pattern of one antenna ANT1 to the angle of the strong radiation intensity of the other antenna ANT2. Further, by changing the installation angle of the vertically polarized wave and the horizontally polarized wave and the antenna, the polarization planes of the antenna can be mutually changed.

Next, the oscillation circuit of the third embodiment of the radio transmitting apparatus of the present invention will be explained with reference to FIG. The oscillator circuit 30 of the present embodiment is the oscillator circuit 1 of the first embodiment shown in FIG.
In addition to 0, the antenna ANT3 is connected in parallel with the oscillator Re in place of the matching coil in the subsequent stage of the oscillator Re. Others are the same as those in FIG. 1, so the same reference numerals as those in FIG.

Also in the oscillation circuit 30 of this embodiment, the second
Like the oscillator circuit 20 of the embodiment, the antenna is the antenna A.
Since there are two antennas, NT1 and ANT3, by changing the directions of these antennas, it is possible to eliminate the null points of the radiation pattern of the antennas, to flatten the directional characteristics, and to change the plane of polarization.

Next, an oscillator circuit of a fourth embodiment of the wireless transmitter of the present invention will be described with reference to FIG. In the oscillator circuit 40 of this embodiment, the antenna ANT1 of the oscillator circuit 20 of the second embodiment shown in FIG.
Only, the variable capacitor Cvp for phase adjustment is connected in parallel to the antenna ANT2. Others are the same as those in FIG. 2, so the same reference numerals as those in FIG.

The oscillator circuit 40 of this embodiment is an antenna AN.
With the variable capacitor Cvp connected in parallel with T2, the phase amount of the oscillation loop can be adjusted to finely adjust the oscillation frequency, and the oscillation output can also be adjusted.

Next, an oscillator circuit of a fifth embodiment of the wireless transmitter of the present invention will be described with reference to FIG. The oscillator circuit 50 of this embodiment is obtained by removing the variable capacitor Cvp connected in parallel to the antenna ANT2 of the oscillator circuit 40 of the fourth embodiment shown in FIG. 4 and connecting the variable capacitor Cvs in series to the antenna ANT2. . Others
Since it is the same as FIG. 4, the same numbers as in FIG.

The oscillator circuit 50 of this embodiment is an antenna AN.
With the variable capacitor Cvs connected in series to T2, the phase amount of the oscillation loop can be adjusted to finely adjust the oscillation frequency, and the oscillation output can also be adjusted, as in the oscillation circuit 40 of the fourth embodiment. it can.

Next, an oscillation circuit of a sixth embodiment of the wireless transmission device of the present invention will be described with reference to FIG. The oscillator circuit of this embodiment is composed of a feedback oscillator circuit 60. The feedback oscillation circuit 60 comprises an oscillation loop composed of the amplifier A and the filter oscillator Re, and the matching coil L3 is connected to the front stage of the filter oscillator Re and the antenna ANT is connected to the ground from the rear stage thereof. is there. Therefore, the phase matching coil L2 in the conventional feedback type oscillation circuit shown in FIG. 11 is replaced with the antenna ANT4, and the capacitor C3 and the antenna ANT connected to the output terminal of the amplifier A are removed.

The feedback type oscillating circuit 60 of this embodiment forms an oscillation loop with the amplifier A and the filter type resonator Re,
A coil L3 and an antenna ANT4 are added to these to form a phase shift type oscillation circuit. The output of the amplifier A is continuously oscillated by being positively fed back to the input of the amplifier A with a phase delay of 180 ° via the coil L3, the filter oscillator and the antenna ANT. In this way, the oscillation energy generated by the oscillation loop is mainly radiated as a radio wave from the antenna ANT4.

Next, an oscillation circuit of a seventh embodiment of the wireless transmission device of the present invention will be described with reference to FIG. The oscillator circuit of this embodiment is composed of a feedback oscillator circuit 70. This feedback oscillator circuit 70 is obtained by replacing the coil L3 of the feedback oscillator circuit 60 shown in FIG. 6 with an antenna ANT. Others are the same as those in FIG. 6, so the same reference numerals as those in FIG. 6 are given and the description thereof is omitted.

In the feedback oscillator circuit 70 of this embodiment, the antennas ANT4 and ANT5 acting as phase matching coils are connected to both sides of the filter oscillator Re, so that these antennas ANT4 and ANT5 are in phase. The rotation is performed and radio waves are emitted from these. Then, by changing the directions of the antennas ANT4 and ANT5, it is possible to eliminate the null point of the radiation pattern of the antenna, to flatten the directional characteristics, and to change the plane of polarization.

Next, an oscillation circuit of an eighth embodiment of the wireless transmission device of the present invention will be described with reference to FIG. The feedback type oscillation circuit 80 of the present embodiment is such that the variable capacitor Cvp for phase adjustment is connected in parallel to the antenna ANT4 of the feedback type oscillation circuit 60 shown in FIG. Others are the same as those in FIG. 6, so the same reference numerals as those in FIG. 6 are given and the description thereof is omitted.

The feedback type oscillation circuit 80 of this embodiment comprises a variable capacitor Cvp for phase adjustment in parallel with the antenna ANT4.
Since it is connected, the precise oscillation frequency and radiation output characteristics can be adjusted.

Next, an oscillation circuit of a ninth embodiment of the wireless transmission device of the present invention will be described with reference to FIG. The feedback oscillator circuit 90 of the present embodiment removes the variable capacitor Cvp for phase adjustment connected in parallel from the antenna ANT4 of the feedback oscillator circuit 80 shown in FIG. A variable capacitor Cvs for phase adjustment is connected toward the ground. Others are the same as those in FIG. 8, so the same reference numerals as those in FIG.

The feedback type oscillation circuit 90 of this embodiment comprises a variable capacitor Cvs for phase adjustment in series with the antenna ANT4.
Since it is connected, it is effective when precise frequency adjustment or radiation output characteristics are required, as in the eighth embodiment.

Although the Colpitts type oscillation circuit and the feedback type oscillation circuit have been described as examples of the oscillation circuit in each of the above embodiments, the Hartley oscillation circuit, the base tuning oscillation circuit, the collector tuning oscillation circuit, and the Wien bridge oscillation circuit have been described. A conventionally known oscillator circuit such as is applied. Further, although the variable capacitor is exemplified as the element for phase adjustment, a variable coil or a variable resistor may be used.

[0033]

According to the present invention, since the antenna is used in place of the matching coil of the oscillator in the oscillation circuit, the excitation power of the antenna is increased and the efficiency in the oscillation loop is also improved. That is, since the power other than the power used for radiation by the antenna is used as it is to maintain the oscillation in the oscillation loop, the power supplied to maintain the oscillation in the oscillation loop is reduced, and the power consumption of the oscillation amplification element is reduced. This is because it is possible to reduce

Further, in the present invention, when the antenna is connected to the latter stage of the oscillator, the harmonic component other than the fundamental wave can be removed from the radiated radio wave by the filter effect of the oscillator.

Further, in the present invention, when a phase adjusting element such as a capacitor is connected in series with an antenna, a desired oscillation frequency can be precisely adjusted and an oscillation output can also be adjusted. You can

Further, in the present invention, by providing two antennas and changing the directions of these antennas,
The null point of the radiation pattern of the antenna can be eliminated to make the directional characteristic flat. Also, the planes of polarization of the antennas can be changed mutually.

Further, according to the present invention, unlike the conventional antenna, the antenna is not connected to the outside of the oscillation loop, and the antenna is used in place of the matching coil of the oscillation circuit. Therefore, the power consumption is low and the oscillation is performed. The circuit configuration is simple and compact.

[Brief description of the drawings]

FIG. 1 is an oscillator circuit diagram of a first embodiment of a wireless transmission device of the present invention.

FIG. 2 is an oscillator circuit diagram of a second embodiment of the wireless transmission device of the present invention.

FIG. 3 is an oscillator circuit diagram of a third embodiment of the wireless transmission device of the present invention.

FIG. 4 is an oscillator circuit diagram of a wireless transmitter according to a fourth embodiment of the present invention.

FIG. 5 is an oscillator circuit diagram of a wireless transmitter according to a fifth embodiment of the present invention.

FIG. 6 is a feedback oscillator circuit diagram of a sixth embodiment of the wireless transmission device of the present invention.

FIG. 7 is a feedback oscillator circuit diagram of a seventh embodiment of the wireless transmission device of the present invention.

FIG. 8 is a feedback oscillator circuit diagram of an eighth embodiment of the wireless transmission device of the present invention.

FIG. 9 is a feedback oscillator circuit diagram of a wireless transmitter according to a ninth embodiment of the present invention.

FIG. 10 is a Colpitts oscillator circuit diagram of a conventional wireless transmission device.

FIG. 11 is a feedback oscillator circuit diagram of a conventional wireless transmitter.

[Explanation of symbols]

ANT1, ANT2, ANT3, ANT4, ANT5
Antenna Re Oscillator 10, 20, 30, 40, 50 Oscillation circuit 60, 70, 80, 90 Feedback oscillation circuit Cvp, Cvs Phase adjustment variable capacitor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H04B 1/04 H04B 1/04 A

Claims (6)

[Claims] 1. A radio transmission device, wherein an antenna is connected instead of a matching circuit coil of an oscillator in an oscillation circuit, and radio waves are transmitted from the antenna. 2. The wireless transmission device according to claim 1, wherein the antenna is connected in series or in parallel with the oscillator to at least one of a front stage and a rear stage of the oscillator. 3. The radio transmitting apparatus according to claim 1, wherein the antenna is connected in series and in parallel with the oscillator to at least one of a front stage and a rear stage of the oscillator. 4. The wireless transmission device according to claim 1, wherein when the number of the antennas is 2, the antennas have different directional characteristics. Wireless transmitter. 5. The antenna, in series or in parallel,
The wireless transmission device according to any one of claims 1 to 4, wherein a phase adjusting capacitor, a coil, or a resistor is connected. 6. The wireless transmission device according to claim 1, wherein the oscillation circuit includes a Colpitts type oscillation circuit, a negative resistance type oscillation circuit, and a feedback type oscillation circuit.