KR20010097032A - Transmitting and receiving circuit device for use for microwave communication - Google Patents

Abstract

According to the present invention, it is combined with a radio transmission and reception unit for transmitting and receiving radio waves to reduce the size of the wireless communication device, the transmission and reception hybrid that can lower the price, the electric field that is simple and high yield, and also can reduce the conversion loss Provided are a wireless mixer having an amplitude shift modulator having a simple structure that directly modulates a frequency mixer using an effect transistor and a field effect transistor amplifier.

Description

Wireless transceiver circuit device for microwave communication {TRANSMITTING AND RECEIVING CIRCUIT DEVICE FOR USE FOR MICROWAVE COMMUNICATION}

The present invention is applied to a wireless module of the equipment for wireless microwave communication and used as a role for separation of transmission and reception when the transmission and reception frequency is close (Hybrid group: 4-wire to 2-wire, 2-wire to 4-wire and And a frequency mixer (mixer) and an amplitude shifting (ASK) modulation circuit section (amplifier).

In general, a wireless communication device is equipped with a circulator (CIRCULATOR) that acts as a duplexer, a frequency mixer, an amplifier and a modulator. The wireless communication device uses a circulator when the transmission and reception frequency bands are almost the same or close to each other, and the circulator separates the transmission and reception frequencies close to each other to enable frequency division communication. However, separation is around 20 decibels, and manufacturing is difficult at high frequencies, such as microwaves, resulting in poor isolation and high cost.

In the case of time division communication, a transmission / reception switch is used to separate the transmission and reception, but the field effect transistor (FET) or the pin diode (PIN DIODE) used at this time is more expensive, and the frequency is higher, the loss and the separation are worse.

In general, a pin diode or a FET switch is separately used as a switching element in Ask modulation. However, a simple circuit, low cost, and elimination of insertion loss are required.

In addition, a mixer is used in the radio communication circuit device. In general, a mixer uses a diode as a passive element and an FET as an active element. Passive mixers are stable but have a loss of conversion, while active mixers have conversion gains that reduce the size of the system but are easy to oscillate and less productive. Therefore, there is a need for a configuration that is stably driven and capable of conversion gain by the signal of the local oscillator.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wireless transmit / receive circuit device provided with a hybrid splitter capable of transmitting and receiving at a high frequency (for example, microwaves) without requiring a separate circulator. .

Another object of the present invention is to provide a wireless transmit / receive circuit device having an amplitude shift modulation amplifier that directly modulates a field effect transistor without using a pin diode or an MMIC element at an ultra-high frequency.

Another object of the present invention is to provide a wireless transmit / receive circuit device equipped with a field effect transistor which is an active element and having a stable frequency mixer (mixer) while reducing conversion loss.

1 is a block diagram of a transmission and reception circuit device according to an embodiment of the present invention;

2 is a configuration diagram of an amplifier in the circuit device of FIG.

3 is a block diagram of a mixer in the circuit device of FIG.

4 and 5 are configuration diagrams of a hybrid device in the circuit device of FIG.

* Explanation of symbols for the main parts of the drawings

10: radio transceiver circuit device 12: antenna

14: first bandpass filter 16: splitter

20: low noise amplifier 22, 200: mixer

34: modulation amplifier

According to an aspect of the present invention, in the transmission and reception circuit device provided with an antenna, a splitter, a mixer, a plurality of filters, an oscillator, and a modulation amplifier, which is used in wireless communication equipment, the splitter is a hybrid device. A wireless transmission and reception circuit device is provided. Hybrids for transmission and reception separation are symmetrical and asymmetrical, and power dividers and 90 ° hybrids and 180 ° hybrids can be used. When the transmit and receive frequencies are close, the circulator is used in the past, but it is difficult to secure a separation degree of more than 25 decibels at the ultra-high frequency. The hybrid splitter of the present invention can secure separation of 35 decibels or more at very high frequencies (for example, 6 GHz or more), and can be applied to frequency division and time division systems.

According to another aspect of the present invention, in a transmission and reception circuit device, which is used in a wireless communication equipment and is provided with an antenna, a splitter, a mixer, a plurality of filters, and an oscillator, the power located between the oscillator and the splitter. The apparatus further includes an amplifier, wherein the power amplifier comprises a field effect transistor, and the voltage between the gate and the source of the field effect transistor is provided with a wireless transmission / reception circuit device, characterized in that data of negative voltage is applied. The field effect transistor amplifier of the present invention is a modulator that implements an amplitude shift modulator without a separate modulator by controlling a gate voltage. The gate terminal of the FET is connected to a bias voltage application circuit (bias circuit), so that data is not influenced or received by other circuits by the bias circuit. In one embodiment of the present invention, the gate voltage is 0 (zero) V when there is no data, and as the data enters, the gate bias voltage of the field effect transistor is applied at a low negative voltage, whereby the device is destroyed by a gate bias of 0V or more. Can be prevented, and the modulation depth can be designed to be 20 decibels or more. In the embodiment, a high speed operation amplifier was used to obtain a negative voltage. In addition, switching the amplifier with the gate voltage lower than the pinch-off reduces power consumption by eliminating the need for a separate transmit amplifier control when there is no signal.

According to another aspect of the present invention, in a transmission and reception circuit device for use in wireless communication equipment and equipped with an antenna, a splitter, a mixer, a plurality of filters, an oscillator, and a modulation amplifier, the mixer is a field effect transistor. Provided is a wireless transceiver circuit device, which is configured. The frequency mixer (mixer) using the field effect transistor of the present invention uses an active element, but not only performs a stable operation compared to a general active frequency mixer, but also has a conversion loss as small as zero decibels unlike a diode frequency mixer, which is a passive element. It can be implemented. Therefore, even if the gain of the low noise amplifier (LNA) is reduced, the noise figure of the entire system is not significantly deteriorated, thereby reducing the size and cost of the system.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiment of the present invention will be described for the transmission and reception device mounted on the vehicle for use in the intelligent transportation network system. However, the present invention is not limited thereto.

Referring to FIG. 1, an antenna 12 is provided in a wireless transceiver circuit device 10 according to an embodiment of the present invention. The antenna 12 is for transmitting and receiving a radio signal, it is preferable to use a micro strip antenna. The first bandpass filter 14 and the splitter 16 are in turn connected to the antenna 12. In this embodiment, a hybrid device is used as the splitter. This splitter 16 separates transmission and reception.

The splitter 16 is sequentially connected to a low noise amplifier (LNA) 20 and a mixer 22. Band Rejection Filters (BRFs) 18 are located on both sides of the low noise amplifier 20 for low noise amplifying weak signals. In the frequency division system, the BRF 18 uses a dielectric resonator or a hairpin filter having a large Q factor, which is used to prevent a large transmission signal from being received at the receiving end.

From the mixer 22, a low pass filter (LPF: LOW PASS FILTER) 24, an intermediate frequency amplifier (IF AMP) 26, and a second band pass filter 28 are connected, and finally the modulated signal is received. A detector 30 for demodulation is connected in turn. On the other hand, the mixer 22 is connected to a phase locked loop voltage controlled oscillator (PLL VCO) 32, which is a device for generating and fixing a desired frequency signal and for changing the frequency according to a channel. . On the other hand, the oscillator 32 is connected to a high power amplifier (HPA: 34) through the buffer amplifier 33, the modulation amplifier 34 is connected to the splitter 16. . The amplifier 34 is connected to a high speed operation OP amplifier 38. The mixer 22 is a device for converting a high frequency signal into an IF (intermediate frequency) using a field effect transistor. In the OP amplifier 38, it is preferable that data is not distorted during high-speed data transmission by using a high-speed device as an operational amplifier. A positive voltage is applied to the gate terminal of the field effect transistor of the modulation amplifier 34 by adjusting the bias voltage. Do not get caught.

On the other hand, the first and second bandpass filters are used to pass only the frequency of the desired band, it is preferable to use a surface acoustic wave filter, a ceramic filter, a quartz filter and the like. Among the configurations of the transceiver, the configuration and connection relationship except for (1) the amplitude shift amplifier, (2) the mixer, and (3) the hybrid splitter are similar to those of the conventional radio transceiver.

In more detail, the transmission / reception circuit device 10 receives a microwave of 5.845 GHz (gigahertz) from the microstrip antenna 12 at the time of reception and passes only a frequency of a desired band via the bandpass filter 14. And a hybrid splitter 16 used to separate the transmission signal and the reception signal.

4 and 5, the hybrid splitters 100 and 150 will be described. The hybrid splitter 16 is used to separate the transmission frequency and the reception frequency. In the hybrid splitter 6, an antenna end 104 and a receiver end RX 106 are disposed at a position facing 180 degrees of the circular pattern 102. The ground terminal 108 and the transmitting terminal TX 110 which are grounded through the resistor R108 (preferably 50 ohms) in the clockwise direction at the receiving terminal 106 are disposed at equal intervals. The transmission signal passes from the transmitting end 110 to the antenna end 104 and the receiving signal passes from the antenna end 104 to the receiving end 106 only.

In general, the strength of the transmission signal is considerably greater than that of the reception signal. Due to the phenomenon that the signal enters the receiver and amplifies the transmission signal in the low noise amplifier, the strength of the reception signal is reduced and the failure of the low noise amplifier may occur. Can be. Therefore, the inflow of the receiving end of the transmission signal should be minimized. This is called isolation and sufficient isolation should be ensured. In a typical circuit, a duplexer or a circulator is used to secure transmission and reception isolation. However, it is difficult to secure sufficient isolation at high frequencies, and the cost is expensive. The smaller the interval between transmission and reception frequencies, the more isolation. It is difficult to manufacture a filter that can. Therefore, the above embodiment of the present invention uses the hybrid splitter 10 as shown in FIG. As a result, while reducing the loss, it is confirmed that sufficient isolation of the transmit and receive signals can be obtained by transmitting and receiving signals.

5 illustrates another type of hybrid splitter 150. The splitter 150 has a basic configuration similar to that of the splitter 100 of FIG. 3, and a circuit pattern far from both ends between the antenna terminal 154 and the receiving terminal 156 in the rotation circular pattern 152. The wider portion 152A and the wider portion 152B and 152C between the receiving end 156 and the ground end 158, and between the transmitting end 160 and the antenna end 154, the Figure 3 The splitter is different from the splitter 100. Since the splitter has the same loss from the antenna end to the receiving end and the transmitting end to the antenna end, the asymmetrical loss is caused by asymmetrical loss in order to compensate for a relatively small received signal. • A splitter that allows for maximum effect upon reception, which can achieve isolation of more than 35 decibels at 6GHz and above.

Referring back to FIG. 1, the received signal slightly reduces the intensity of the transmitted signal through the dielectric resonator 18, amplifies the received signal through the low noise amplifier 20, and generates an intermediate frequency through the mixer 22. do.

There are several types of mixers, passive mixers and active mixers, the former has the advantage of being stable while having some loss, the latter having gain, not the loss, and the advantage of being able to construct microwave integrated circuits. On the other hand, there is a disadvantage that has the possibility of instability. In the present invention, a mixer using a field effect transistor is used, and in the biasing method, a mixer is implemented using self bias, and its configuration is as follows.

Referring to FIG. 3, first, the mixer 200 includes a field effect transistor 202, which requires a positive voltage between the drain and the source and a negative voltage between the gate and the source. For this reason, it is desirable to simultaneously generate and apply a positive voltage and a negative voltage. A positive voltage is applied to the drain 204 in the form of self-bias, and the source 206 has a capacitor grounded at a lambda / 4 stub, and the gate 208 has a lambda / 4. The stub is grounded.

A signal at the receiving end is applied to the gate 208, an oscillator signal is applied to the source 206, and an intermediate frequency is output through the drain 204. In the present invention, there is almost no potential difference between the voltage applied to the drain 204 and the source 206 voltage, so that the voltage applied to the source 206 through the drain 204 is formed as it is, and the gate ( 208 remains grounded, so a negative voltage is formed between the source 206 and the gate 208. This creates a negative voltage between the gate 208 and the source 206 to facilitate the operation of the field effect transistor 202. Although the mixer 200 has a conversion gain as an active mixer, a sufficient isolation between the received signal and the oscillator signal may not be secured, but as described later, a relatively high gain may be used to demodulate the amplitude-modulated signal. It will be necessary to satisfy this advantage.

Looking at the mixer in detail, the IF side (IF Termination) and the DC block (DC Block) is provided on the gate side. Lo & RF terminations, voltage-sharing resistors and bypass capacitors are provided on the drain side, and a DC block on the IF output side. On the source side, a DC block and IF termination are provided.

Referring back to FIG. 1, the intermediate frequency generated by the mixer 22 passes through the lowpass filter 24, the intermediate frequency amplifier 26, the intermediate frequency bandpass filter 28, and the detector 30 to the desired data. You get Looking at the transmitting end, the voltage control oscillator 32 generates a carrier frequency, which is amplified through the buffer amplifier 33, and then amplified through the high power amplifier 34, which is the final stage, to transmit at a desired power. The high power amplifier 34 has a modulation effect of loading data at a carrier frequency. The modulation of this configuration is called direct modulation, and its construction principle is that the field effect transistor is used as a gate-source source as described in the mixer description. It is driven by negative voltage, positive voltage between drain and source.

1 and 2, the amplifier 300 of the present invention uses a voltage between the gate and the source, and uses the negative voltage difference to operate and deactivate the field effect transistor 302 by data. Perform transition direct modulation. At this time, if the voltage between the gate and the source has a positive voltage of more than 0 volts, the field effect transistor will fail, so it should always be kept below 0 volts. However, since the voltage of the data is a positive voltage of 0 volts or more, it should be changed to a negative voltage and applied to the gate. To this end, the data is applied to the operational amplifier 38, and the operational amplifier 38 converts the negative voltage into a form of a negative voltage, which is then applied to the gate 302. It is desirable that the potential difference with the subject data is always a negative voltage. By this operation, the amplitude shift is directly modulated. The modulated transmission signal is transmitted through the hybrid splitter 16.

The amplifier will be described in detail. If a line is connected to the gate (which performs the operating frequency bypass function) through a connection that prevents leakage of the operating frequency, the λ / 4 radial stub will have a stability improving resistor (data line and bias). Separation function) and then RF choke. The line on the gate side is connected to the amplifier 38.

As above, when the λ / 4 radial stub is connected to the gate (which performs the operating frequency bypass function) through a connection that prevents leakage of the operating frequency, the λ / 4 radial stub has a stability improving resistance. (The function of separating the data line and the bias), followed by the RF choke.

Although the present invention has been described with reference to the above embodiments, the present invention is not limited thereto. Those skilled in the art will appreciate that modifications, changes, and the like may be made without departing from the spirit and scope of the present invention, and such modifications and changes also belong to the present invention.

According to the above configuration of the present invention, a wireless transmission / reception circuit device provided with a splitter capable of transmitting and receiving separation at a high frequency (for example, microwave) without requiring a separate circulator is provided. In addition, it is possible to use an amplitude shift modulation amplifier that directly modulates using a field effect transistor without using a pin diode or an MMIC device at very high frequencies. Third, there is provided a wireless transmission / reception circuit device equipped with a field effect transistor which is an active element and having a stable frequency mixer (mixer) while reducing conversion loss.

Claims (7)

In a transmission and reception circuit device for an antenna, a splitter, a mixer, a plurality of filters, an oscillator, and a modulation amplifier, which is used in wireless communication equipment, The splitter is a wireless transceiver circuit device, characterized in that the hybrid. The wireless transceiver circuit device according to claim 1, wherein the hybrid device is asymmetrical. In a transmission and reception circuit device for an antenna, a splitter, a mixer, a plurality of filters, an oscillator, and a modulation amplifier, which is used in wireless communication equipment, And the mixer comprises a field effect transistor. In the transmission and reception circuit device used in the wireless communication equipment and equipped with an antenna, a splitter, a mixer, a plurality of filters, and an oscillator, Further comprising a power amplifier located between the oscillator and the splitter, the power amplifier is composed of a field effect transistor, The voltage between the gate and the source of the field effect transistor is a wireless transmission and reception circuit device, characterized in that the data of the negative voltage is applied. The wireless transceiver circuit device according to claim 3 or 4, wherein the splitter is a hybrid device. 6. The wireless transmit / receive circuit device according to claim 4 or 5, wherein the mixer comprises a field effect transistor. The wireless transceiver circuit according to any one of claims 4 to 6, wherein the negative voltage between the gate and the source is obtained from a high speed operation amplifier.