KR20120027759A - Two way radio communication module - Google Patents

Abstract

PURPOSE: A bi-directional radio communication module for transmitting and receiving an RF signal is provided to divide a receiver path and a transmitter path and to install an RF process path, a power unit, and a digital processing unit on mutually different PCBs. CONSTITUTION: A first switching unit(14a) and a second switching unit(14b) are installed to a connection part of an input terminal of a receiving unit(12) and an output terminal of a transmitting unit(13). The switching unit selects the path of the receiver or the transmitter. A switching controlling unit(16) controls the first switching unit and the second switching unit.

Description

TWO WAY RADIO COMMUNICATION MODULE}

The present invention relates to a bidirectional wireless communication module, and more particularly, to a bidirectional wireless communication module for a low power wireless device applied to a wireless communication field such as Bluetooth, Zigbee, Binary CDMA, etc. It is about.

In general, wireless communication refers to communication using electromagnetic waves without using wires, and includes those that directly transmit a communication signal in the form of electromagnetic waves, or reflect and transmit and communicate with an ionosphere or communication satellite in the atmosphere. It is called Radio Frequency (RF).

For reference, referring to an example of the conventional wireless communication of the part to which the present invention is applied, first, Bluetooth, which is a standard for wireless communication at low power in a short range between wireless communication devices, may be exemplified. Brutus's purpose is to transfer information between devices such as mobile computers, mobile phones, headsets, personal digital assistants (PDAs), personal computers (PCs), and printers.

Next, ZIGBEE, which is a standard technology for home automation and data networks with a low transmission rate, is an example. The ZigBee is a technology that started from the one-button operation to control the light and home security system VCR on / off anywhere in the house, and to use home automation more conveniently by dial-up via the Internet. . The Zigbee is standardized in IEEE 802.15.4, and the dual PHY type uses 2.4GHz and 868 / 915MHz frequency bands, and the modem method is a direct sequence spread spectrum (DS-SS). 250 kbps.

Next, binary CDMA is a modem technology that binarizes analog signal magnitude changes with various level values generated by conventional DS / CDMA technology to externally look like time division multiple access (TDMA) signal waveforms. (Binary CDMA) is an example. The binary CDMA has a binary waveform form, which simplifies the signal processing process and does not require the linearity of the transmission system, thereby simplifying the overall system structure and enabling the transmission of multi-channel code division multiple access (CDMA) signals using conventional TDMA RF. Therefore, it is possible to develop a low power, miniaturized system using an RF module for Bluetooth or public wireless LAN service (WLAN).

In addition, TRS communication, which provides a communication standard for multiple users to use one frequency band in common, and general CDMA communication, frequency, which provides a communication standard for allowing multiple users to access a service in the same frequency band. For example, VHF / UHF communication using microwave in the region of about 30 to 300 MHz and microwave in the region of about 300 to 3000 MHz may be used.

The wireless communication as described above is implemented through a communication module. Referring to the bidirectional communication module for conventional wireless communication as an example, an antenna for transmitting and receiving RF (high frequency radio signal); An amplifier for amplifying a signal received through the antenna or a signal to be transmitted; A filter unit for collecting only a desired signal among the signals received through the antenna, selecting and transmitting only a signal to be transmitted, or preventing noise interference and interference between components, for example, circuits, on a transmission / reception process path; And a matching unit matching the impedance between the input and output portions.

Such a conventional two-way wireless communication module is designed to be arranged on a printed circuit board (PCB), because a plurality of electronic devices are integrated in the two-way wireless communication module, interference between a plurality of electronic devices may occur, accordingly bidirectional wireless Characteristic degradation is caused by the RF performance of the communication module, for example, by reducing the transmission / reception distance or noise.

The present invention created to solve the problems of the prior art as described above by separating the path of the receiver and the transmitter, by providing the RF processing path, ground (ground), power supply and digital processing unit on the printed circuit board of different layers, It aims to provide two-way wireless communication module which can transmit / receive RF signal without loss and can prevent noise interference and interference between each circuit.

The present invention for achieving the above object is an antenna 11, a receiver 12 for receiving a signal flowing from the antenna 11 to the transmission / reception processing unit 15 and the transmission / reception processing unit 15 In the two-way wireless communication module 10 comprising a transmitting unit 13 for transmitting the signal transmitted from the) to the antenna 11, the antenna 11 side and the transmission / reception processing unit 15 side In the input terminal and the output terminal connecting portion of each of the receiving unit 12 and the transmitting unit 13 located at the switching unit 1, 2 (14a) 14b for selecting the path of the receiving unit 12 or the transmitting unit 13, respectively, It is characterized in that the switching control unit 16 for controlling the switching unit 1, 2 (14a, 14b) by a separate input signal.

The present invention of the above-mentioned problem solving means is to separate the path of the receiving unit and the transmitting unit, while providing the RF processing path, ground (ground), power supply unit and digital processing unit on different layers of printed circuit board, without loss of RF signal By allowing transmission and reception, communication distance can be extended, and noise interference and interference between circuits can be prevented, thereby improving RF performance of the bidirectional wireless communication module.

1 is a block diagram schematically showing a configuration according to an embodiment of the present invention.
Figure 2 is a block diagram showing in more detail the configuration according to an embodiment of the present invention.
3 is a block diagram schematically showing a configuration according to another embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, the present invention, as shown in Figure 1 and 2 of the accompanying drawings, the receiving unit 12 for receiving the antenna 11, the signal flowing from the antenna 11 and transmitting to the transmission / reception processing unit 15 And a transmitting unit 13 which transmits a signal transmitted from the transmitting / receiving processor 15 to the antenna 11 so that the signal is transmitted. The bidirectional wireless communication module 10 includes: Switching section 1, 2 (14a) which selects a path of the receiving section 12 or the transmitting section 13 at the input and output connection portions of the receiving section 12 and the transmitting section 13 located on the transmitting / receiving section 15 side. 14b may be provided respectively, and the switching controller 16 may be provided to control the switching units 1, 2 (14a) and 14b by separate input signals.

 Here, the receiver 12 of the present invention includes a low noise amplifier circuit 12a for low-noise amplifying the RF signal received from the antenna 11 to the switching unit 2 (14b) side; And an impedance matching circuit 12b for matching the impedance of the antenna 11 side with the low noise amplifier circuit 12a.

In this case, the low noise amplifier circuit 12a may be a high frequency amplifier circuit for lowering the noise figure of the receiver 12 as a whole. The noise figure may be designed to be minimum and the gain value may be designed to be 15 dB.

For reference, the power received by the RF receiver has a very low power level due to the effects of attenuation and noise. Therefore, it is necessary to amplify the signal. Amplification is required.

The low-noise amplifier circuit 12a preferably employs a transistor having a low noise figure and a circuit that uses a small current as well as a low noise figure in order to create a low noise characteristic, and uses a parameter amplifier and a low noise transistor. An amplifier such as an amplifier or a major may be applied.

In addition, the impedance matching circuit 12b may be a circuit connecting the antenna 11 side (output terminal) and the low noise amplification circuit 12a side (input terminal) to minimize reflection due to their impedance difference.

The impedance matching circuit 12b may include an intermediate impedance of 1/4 wavelength length inserted between the antenna 11 side and the low noise amplification circuit 12a side, and the low noise amplification side of the antenna 11 side. It may be a short line vertically drawn out from the connection end or the circuit side of the circuit 12a side, or may be a direct connection of the LC element.

In this case, an output terminal of the low noise amplifier circuit 12a may be connected to the switching unit 2 14b, and an input terminal of the impedance matching circuit 12b may be connected to the switching unit 1 14a.

On the other hand, the transmission unit 13 of the present invention is a power amplifier circuit 13a for amplifying the RF signal transmitted from the transmission and reception processing unit 15 to a high power of a desired level to the antenna (11) side; And a harmonic signal and a spurious signal generated by the power amplifier circuit 13a and the transmit / receive processor 15, and the output side and the switching unit 1 of the power amplifier circuit 13a. And a bandpass filter / matching circuit 13b for matching impedances between the input sides of the 14a.

In this case, the power amplifier circuit 13a may be a class A power amplifier with an operating point biased such that at least half of the output signal swing does not exceed the high voltage level, the low voltage level, or 0V limited by the supply voltage level.

The Class-A power amplifier operates in a linear region with respect to all phases of 360 degrees because the operating point is almost at a median, so there is no signal distortion.

In addition, the band filter / matching circuit 13b is a band pass filter (BPF) for passing only electromagnetic waves having a certain range, that is, a frequency belonging to a band, and blocking all others, and a matching circuit such as the impedance matching circuit 12b described above. It may be configured to include.

The band pass filter may be made of a general coil and a capacitor, or may be made of a piezoelectric crystal that vibrates freely. (This crystal vibrates mechanically when a voltage is applied with the same frequency as its resonance frequency.)

In the above, when the output of the impedance matching and the power amplifier circuit 13a is 18dBm, it is possible to lower the maximum performance of the power amplifier circuit 13a, the same when using the maximum output of the power amplifier circuit 13a at 23dB and 20dB In the case of 18dB output, the current consumption is lower when configuring the maximum output at 20dB than when configuring the maximum output at 23dB. (The current consumption varies greatly depending on the impedance matching.)

Meanwhile, in the present invention, the switching units 1, 2 (14a, 14b) open or close or conduct / block the input / output paths of the receiving unit 12 and the transmitting unit 13 by the control signal of the switching control unit 16. It may be a switching means.

The switching means may be a logic circuit or a switching element itself which drives when an operation signal is input to open / close or conduct / block the input / output paths of the receiver 12 and the transmitter 13.

At this time, the switching unit 1 (14a) may be connected to the input side is connected to the antenna 11 side, the output side is connected to the receiver 12 side, the other input side may be connected to the transmitter 13 side.

In addition, the switching unit 2 (14b), the input side is connected to the receiving unit 12 side, the output side may be connected to the transmitting unit 13 side, the other input / output side may be connected to the transmission / reception processing unit 15 side.

In addition, the switching units 1, 2 (14a, 14b) turn on the power of the low noise amplifier circuit 12a and turn off the power of the power amplifier circuit 13a when the receiver 12 is opened (conducted). When the transmitter 13 is opened (conducted), a switching operation of turning on the power of the power amplifier circuit 13a and turning off the power of the low noise amplifier circuit 12a may be performed.

In this case, in the situation where only one of the receiver 12 and the transmitter 13 operates, the power supply of the other part is cut off at the source, thereby preventing unnecessary current consumption.

On the other hand, in the present invention, the transmission / reception processing unit 15 provides an RF signal received to the final output side, and transmits an RF signal input from the RF signal park to the transmission unit 13 side (15a); And an RF matching circuit 15b for matching an impedance between an input / output terminal of the RF transceiver 15a and an input / output terminal of the switching unit 214b.

In this case, the RF transceiver 15a may be a CC2400 or nRF2401 of a Gaussian frequency-shift keying (GFSK) or a CC2420 of a ZigBee chip.

The Gaussian frequency shift is one of frequency shift keying (FSK). An IC chip or IC chip converts binary 1 to positive deflection and binary 0 to negative deflection using a Gaussian filter. It may be a discrete circuit including a.

In the above, the CC2400 is a 2.4GHz band data transmission IC capable of transmitting and receiving short-range data regardless of international standards such as ZIGBEE and Bluetooth. The maximum speed is 1Mbps, but it is applied to an application having a speed of about 800Kpbs in consideration of the actual error rate. This will be possible.

In addition, the nRF2401 is a communication module having a frequency band of 2.4 GHz to 2.5 GHZ.

In addition, the CC2420 is a wireless transmit / receive chip supporting IEEE 802.15.4 wireless communication. The CC2420 uses a 2.4 GHz ISM band and may be used for sensor networks and Zigbee.

On the other hand, in the present invention, the switching controller 16 determines whether the transmission / reception processor 15 is a reception operation or a transmission operation so that a program for controlling the operation of the switching units 1, 2 (14a) and 14b is mounted. It may be a microprocessor or control circuit.

The criterion for determining whether the transmitting / receiving processor 15 is a receiving operation or a transmitting operation may be obtained based on the progress direction of the RF signal or the level of the signal.

In addition, the switching controller 16 turns on the power of the low noise amplifier circuit 12a, turns off the power of the power amplifier circuit 13a, and opens the transmitter 13 when the receiver 12 is opened (conducted). In the case of (conduction), a switching operation control signal for turning on the power of the power amplifier circuit 13a and turning off the power of the low noise amplifier circuit 12a may be applied to the switching parts 1, 2 (14a) and 14b. When the receiver 12 is opened, a control signal for directly turning on the power of the low noise amplifier circuit 12a and turning off the power of the power amplifier circuit 13a is output. A control signal for turning on the power supply of the amplifier circuit 13a and turning off the power supply for the low noise amplification circuit 12a may be provided.

In this case, in the situation where only one of the receiver 12 and the transmitter 13 operates, the power supply of the other part is cut off at the source, thereby preventing unnecessary current consumption.

The present invention configured as described above also includes the antenna 11, the receiver 12, the transmitter 13, the switch 1, 2 (14a) 14b, the transmission / reception processor 15 and the switching controller 16. ) Is arranged on the first layer of the RF line and the electrical ground, which is a path related to the transmission and reception of the RF signal, another RF ground on a separate second layer, and a separate power supply unit for supplying power to the bidirectional communication module. And a digital signal processing path and an electrical ground separate from the RF processing portion and the fourth printed circuit board.

In this case, the RF line may be a processing path of the RF signal, and the RF line may be formed in the form of a coplanar waveguide with ground (CPWG) pattern.

The CPWG pattern-shaped antenna may be trapezoidal to obtain wideband characteristics. An H-type patch may be inserted into the trapezoid to stabilize resonance and impedance matching of the antenna. When configured in a form, it is possible to construct a good track on a small board.

Referring to the operation of the present invention as described above is as follows.

First, a reception process of the bidirectional wireless communication module 10 of the present invention will be described.

When the RF signal is received through the antenna 11, the transmission / reception processing unit 15 is in a reception state. At this time, the switching control unit 16 controls the switching unit 1 14a and the switching unit 2 14b. By receiving the signal, the RF reception signal is guided only to the path of the receiver 12 and is blocked at the source from the transmitter 13.

As described above, the RF signal guided to the receiving unit 12 has an impedance matching circuit 12b matching the impedance between the antenna 11 and the low noise amplifier circuit 12a, and the low noise amplifier circuit 12a Amplify the low noise signal and level up to a processable signal.

When the signal leveled up to the processable state is input to the RF matching circuit 15b of the transmission / reception processing section 15 via the switching section 2 14b, the RF matching circuit 15b enters the RF transceiver 15a. When the impedance between the output terminal and the input / output terminal of the switching unit 2 (14b) is matched and input to the RF transceiver 15a, the RF transceiver 15a inputs the RF signal to the final output side to perform the following processing. .

Next, the transmission process of the bidirectional wireless communication module 10 of the present invention will be described.

When the RF signal is input to the RF transceiver 15a from the RF signal park provided separately from the bidirectional wireless communication module 10 of the present invention, the RF transceiver 15a transmits the input RF signal to the transmitter 13 side. After passing through the RF matching circuit 15b, the impedance between the input / output terminal of the RF transceiver 15a and the input / output terminal of the switching unit 214b is exactly matched to transmit a signal without loss.

The switching controller 16 determines the operating state of the RF transceiver 15a and transmits a control signal to the switching unit 2 14b and the switching unit 1 14a, thereby transmitting the RF transmission signal to the path of the transmitting unit 13. Only induces and blocks with the receiving unit 12 at source.

As described above, the RF transmission signal induced to the transmitting unit 13 side is amplified to a level that the power amplifier circuit 13a can transmit, and the band filter / matching circuit 13b removes the harmonic signal and the spurious signal generated at this time (band Through a pass-through filter (BPF) and a low pass filter (LPF).

In the above description, the harmonic signal is a kind of noise signal due to coral modulation or intermodulation, and the spurious signal refers to a signal that comes out of a predetermined band, including unnecessary harmonics and harmonics other than the frequency desired by the wireless transmitter. This is called spurious copying or unnecessary copying, which is copied to space, and it is strictly limited to a certain limit by radio wave method because it interferes with other communication.

As described above, after performing the band filter / matching circuit 13b, the antenna 11 performs impedance matching with the switching unit 1 14a to obtain only an intact RF signal for transmission and transmit the signal without loss. Send via

At this time, the power amplifier circuit 13a for amplifying the RF signal is set to the maximum output to increase the communication efficiency of the wireless communication module.

According to the present invention as described above, by matching the output side of the transmitter with the switching unit so that the signal can be transmitted without loss, the communication distance can be extended.

As described above, according to the present invention, the antenna 11, the receiving unit 12, the transmitting unit 13, the switching unit 1, 2 (14a) 14b, the transmission / reception processing unit 15 and the switching control unit 16 ) Is arranged on the first layer of the RF line and the electrical ground, which is a path related to the transmission and reception of the RF signal, another RF ground on a separate second layer, and a separate power supply unit for supplying power to the bidirectional communication module. It can be designed on a multi-layer printed circuit board arranged in layers and having RF processing parts and digital signal processing paths and electrical ground separate from the fourth layer. Minimize and deliver the maximum signal.

In addition, the present invention is to separate the path of the receiver and the transmitter, while providing the RF processing path, ground (ground), power supply and digital processing unit on the printed circuit board of different layers to prevent noise interference and interference between each circuit, The RF performance of the two-way wireless communication module can be improved.

As another embodiment of the present invention, as shown in FIG. 3, a transformer 17 for outputting by adjusting the level of an input signal to a set level between the antenna 11 and the switching unit 1 14a. It can also be provided.

In this case, even if the impedance of the antenna 11 is not 50 ohms, the input / output impedances of the low noise amplifier circuit 12a and the power amplifier circuit 13a do not change. It does not affect the output.

If the transformer 17 is absent, when the impedance of the antenna 11 is 58 ohms, power amplification and low noise amplification are performed by mismatching the antenna 11 and the low noise amplifier circuit 12a or the power amplifier circuit 13a. The characteristics of, and the output and current consumption may change accordingly.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

In addition, those skilled in the art will appreciate that many modifications and variations of the present invention are possible without departing from the spirit and scope of the appended claims.

Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

10: two-way wireless communication module 11: antenna
12: receiver 12a: low noise amplifier circuit
12b: impedance matching circuit 13: transmitter
13a: power amplifier circuit 13b: band pass filter / matching circuit
14: switching section 14a, 14b: switching section 1,2
15: transmitting and receiving processing unit 15a: RF transceiver
15b: RF matching circuit 16: switching controller

Claims (11)

An antenna 11, a receiver 12 for receiving a signal flowing from the antenna 11 and transmitting the signal to the transmit / receive processor 15 and a signal transmitted from the transmit / receive processor 15 to the antenna 11. In the two-way wireless communication module 10 including a transmitting unit 13 to be transmitted to the transmission),
Switching for selecting a path of the receiver 12 or the transmitter 13 at the input and output terminal connection portions of the receiver 12 and the transmitter 13 positioned on the antenna 11 side and the transmitter / receive processor 15 side. Bi-directional wireless, characterized in that the first and second (14a) and 14b are provided, respectively, and the switching control unit 16 for controlling the switching unit 1, 2 (14a, 14b) by a separate input signal. Communication module. The method of claim 1,
The receiver 12 includes a low noise amplifier circuit 12a for low noise amplifying the RF signal received from the antenna 11 and outputting the signal to the switching unit 2 14b; And an impedance matching circuit (12b) for matching the impedances of the antenna (11) side and the low noise amplification circuit (12a). The method of claim 1,
The transmission unit 13 includes: a power amplifier circuit 13a for amplifying the RF signal transmitted from the transmission and reception processor 15 to a high level of desired power and outputting the antenna signal to the antenna 11 side; And removing the harmonic signal and the spurious signal generated by the power amplifier circuit 13a and the transmit / receive processor 15, and adjust the impedance between the output side of the power amplifier circuit 13a and the input side of the switching unit 1 14a. And a matching band filter / matching circuit (13b).
The method of claim 1,
The switching units 1, 2 (14a, 14b) are switching means for opening and closing or conducting / blocking the input / output paths of the receiving unit 12 and the transmitting unit 13 by the control signal of the switching control unit 16. Two-way wireless communication module. The method of claim 1,
The transmitting / receiving processor 15 includes: an RF transceiver 15a for providing a received RF signal to a final output side and transferring an RF signal input from an RF signal park to a transmitting unit 13 side; And an RF matching circuit (15b) matching an impedance between an input / output terminal of the RF transceiver (15a) and an input / output terminal of the switching unit (2b). The method of claim 1,
The switching controller 16 determines whether the transmitting / receiving processor 15 is a receiving operation or a transmitting operation to control the operation of the switching units 1, 2 (14a) and 14b. Bidirectional wireless communication module characterized in that the circuit.
The method of claim 1,
The antenna 11, the receiving unit 12, the transmitting unit 13, the switching unit 1, 2 (14a) 14b, the transmission / reception processing unit 15 and the switching control unit 16 is a path associated with the transmission and reception of RF signals The RF line and the electrical ground are arranged on the first layer, the other RF ground is placed on a separate second layer, and a power supply unit for supplying power to the bidirectional communication module is placed on a separate third layer, A bidirectional wireless communication module characterized by designing a separate digital signal processing path and electrical ground on a multilayer printed circuit board arranged on the fourth layer.
The method of claim 1,
The switching sections 1, 2 (14a, 14b) turn on the power of the low noise amplifier circuit 12a when the receiver 12 is open (conduct), and turn off the power supply of the power amplifier circuit 13a. And a switching operation for turning on the power of the power amplifier circuit (13a) and turning off the power of the low noise amplifier circuit (12a) when the transmitter (13) is opened (conducted). The method of claim 1,
The switching controller 16 turns on the power of the low noise amplifier circuit 12a when the receiver 12 is opened, turns off the power of the power amplifier circuit 13a, and amplifies power when the transmitter 13 is opened. And a switching operation control signal for turning on the power of the circuit (13a) and turning off the power of the low noise amplification circuit (12a) to the switching sections 1, 2 (14a) and (14b). The method of claim 1,
When the receiver 12 is opened, the switching controller 16 directly turns on the power of the low noise amplifier circuit 12a and outputs a control signal for turning off the power of the power amplifier circuit 13a. 2) A two-way wireless communication module for outputting a control signal for directly turning on the power of the power amplifier circuit 13a and for turning off the power of the low noise amplifier circuit 12a. The method of claim 1,
The two-way wireless communication module, characterized in that between the antenna 11 and the switching unit 1 (14a) is provided with a transformer (17) for adjusting and outputting the level of the input signal to a set level.

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