A matching network capable of realizing path selection

Abstract

The present invention discloses a matching network capable of realizing path selection, which is applied to a radio frequency transceiver path structure, and includes a matching unit, a resonance unit and a control unit; when the radio frequency transceiver path needs to be turned on, the control unit controls the resonance unit to not work, and at the same time enables the matching unit to play a matching role in the radio frequency transceiver path, and the radio frequency input signal is output after passing through the matching unit, so as to realize the matching and conduction of the radio frequency transceiver path; when the radio frequency transceiver path needs to be disconnected, the control unit controls the resonance unit and the matching unit to generate parallel resonance, and blocks the radio frequency signal from passing through, so as to realize the path disconnection. The present invention can effectively reduce the path insertion loss, improve the transmission power of the transmission path, and reduce the noise coefficient of the receiving path.

Description

Technical Field

[0001] The invention belongs to the technical field of wireless communication. Background Art

[0002] In radio frequency systems, it is usually necessary to switch between multiple channels, such as phased array systems and mobile communication radio frequency systems. Figure 1 The typical RF transceiver path diagram is given. The transceiver system has three ports, the common end, the transmitting end and the receiving end. The paths of the transmitting channel and the receiving channel are shown by the arrows in the figure. When the transmitting channel is working, the path switching switch T2 is closed and T1 is disconnected. The transmitting signal first passes through the PA (power amplifier) ​​from the transmitting end, then passes through the matching network, and finally passes through T2 to reach the output end; when the receiving channel is working, the path switching switch T1 is closed and T2 is disconnected. The receiving RF signal first passes through T1 from the common end, and then passes through the LNA (low noise amplifier) ​​to reach the receiving end.

[0003] In the RF system, the transmitting channel hopes that the transmitting power is as high as possible to meet the coverage requirements, but the path switching switch will introduce loss. At >5GHz, the loss is even greater than 1dB. This will seriously affect the coverage of the transmitting channel. In order to compensate for this 1dB loss, the PA must provide more power, which increases the difficulty of PA design and increases the cost and power consumption. The receiving channel hopes that the noise is as small as possible. The insertion loss introduced by the path switching switch will also worsen the receiving channel noise and affect the receiving sensitivity. Summary of the invention

[0004] Purpose of the invention: In order to solve the problems existing in the above-mentioned prior art, the present invention provides a matching network that can realize path selection.

[0005] Technical solution: The present invention provides a matching network capable of realizing path selection, which is applied to a radio frequency transceiver path structure and includes a matching unit, a resonance unit and a control unit;

[0006] When the RF transceiver path needs to be turned on, the control unit controls the resonance unit not to work, and at the same time enables the matching unit to play a matching role in the RF transceiver path. The RF input signal is output after passing through the matching unit, thereby realizing the matching and conduction of the RF transceiver path; when the RF transceiver path needs to be disconnected, the control unit controls the resonance unit and the matching unit to generate parallel resonance, blocking the RF signal from passing through, thereby realizing the path disconnection.

[0007] Further, the matching unit includes an inductor and a first capacitor; the resonance unit includes a second capacitor;

[0008] When the resonant frequency of the inductor and the first capacitor is less than the operating frequency of the RF transceiver path, the control unit includes a first switch and a second switch; one end of the inductor is connected to one end of the second switch, and the other end of the inductor is connected to one end of the first capacitor; the other end of the first capacitor is connected to one end of the second capacitor and an end of the first switch, the other end of the first switch is grounded, and the other end of the second capacitor is connected to the other end of the second switch;

[0009] When the resonant frequency of the inductor and the first capacitor is greater than the operating frequency of the RF transceiver path, the control unit includes third to fifth switches; one end of the inductor is connected to one end of the fifth switch, the other end of the inductor is connected to one end of the first capacitor and one end of the second capacitor, the other end of the first capacitor is connected to one end of the third switch and one end of the fourth switch, and one end of the fourth switch is also connected to the other end of the fifth switch; the other end of the third switch is grounded; and the other end of the fourth switch is connected to the other end of the second capacitor.

[0010] Beneficial effects:

[0011] 1. The present invention can effectively reduce the path insertion loss, increase the transmission power of the transmission path, and reduce the noise coefficient of the receiving path.

[0012] 2. Due to the reduction of path insertion loss, the performance requirements for PA and LNA are also reduced, and the present invention reduces the cost of PA and LNA.

[0013] 3. The present invention reduces the PA transmission power requirement, thereby significantly reducing the energy consumption of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural diagram of a radio frequency transceiver path in the prior art;

[0015] Figure 2 The circuit principle diagram of the present invention is when the resonant frequency in the matching unit is lower than the operating frequency of the RF transceiver path;

[0016] Figure 3 : is a working principle diagram of the circuit of the present invention, wherein (a) is a state diagram of each switch of the circuit when the path is turned on, (b) is an equivalent circuit diagram of Figure (a), (c) is a state diagram of each switch of the circuit when the path is turned off, and (d) is an equivalent circuit diagram of Figure (c);

[0017] Figure 4 This is a comparison diagram of insertion loss between the present invention and the prior art;

[0018] Figure 5 This is a comparison diagram of the present invention and the existing solution;

[0019] Figure 6It is a circuit principle diagram of the present invention when the resonant frequency in the matching unit is greater than or equal to the operating frequency of the radio frequency transceiver path. DETAILED DESCRIPTION

[0020] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0021] The present invention aims to utilize the existing matching network of the amplifier to realize the conduction and cutoff of the path through different resonance characteristics, thereby eliminating the switching devices in the traditional structure, reducing the path loss and improving the transmission power.

[0022] When the RF transceiver path needs to be turned on, the control unit controls the resonance unit not to work, and at the same time enables the matching unit to play a matching role in the RF transceiver path. The RF input signal is output after passing through the matching unit, thereby realizing the matching and conduction of the RF transceiver path; when the RF transceiver path needs to be disconnected, the control unit controls the resonance unit and the matching unit to generate parallel resonance, blocking the RF signal from passing through, thereby realizing the path disconnection.

[0023] The matching unit of the present invention is composed of inductors L1 and C1. When the resonant frequency of the inductors L1 and C1 in the matching unit is lower than the operating frequency of the RF transceiver path, the specific structure of the present invention is as follows: Figure 2 As shown: the matching unit is composed of inductor L1 and capacitor C1, L1 port 1 is connected to RF port RF2 (that is, Figure 1 The output end of the PA in the middle), port 2 of L1 is connected to the RF port RF1 (that is, Figure 1 The common end in the control unit); C1 port 1 is connected to L1 port 1, and C1 port 2 is connected to T1 port 1 in the control unit. The resonant unit is composed of capacitor C2, C2 port 1 is connected to T2 port 1 in the control unit, and C2 port 2 is connected to C1 port 2 in the matching unit and T1 port 1 in the control unit. The control unit is composed of switch T1 and switch T2, switch T1 port 1 is connected to C1 port 2 in the matching unit and C2 port 2 in the resonant unit, and switch T1 port 2 is grounded; switch T2 port 1 is connected to C2 port 1 in the resonant unit, and switch T2 port 2 is connected to RF port RF1 and L1 port 2 in the matching unit.

[0024] The specific working principle of the present invention is as follows Figure 3 shown. Figure 3 (a) shows the state of each switch when the path is turned on, where T1 is closed and T2 is open. The equivalent circuit is as follows Figure 3 As shown in (b), it is an L-shaped matching network. At this time, the resonant unit does not work, and the matching unit realizes the normal circuit matching function. Figure 3 (c) shows the state of each switch when the path is disconnected, where T1 is open and T2 is closed. The equivalent circuit is as follows: Figure 3 As shown in (d), it is a parallel resonant circuit. At this time, the resonant unit and the matching unit produce parallel resonance. Ce is the series equivalent capacitance of C1 and C2. By adjusting the value of C2, Ce and L1 resonate at the operating frequency, realizing the function of disconnecting the path.

[0025] In the mobile communication N41 frequency band, the radio frequency path performance comparison between the present invention and the existing solution is shown in Figure 2. Figure 4 and Figure 5 shown. Figure 4 The insertion loss comparison when the path is turned on is given. The insertion loss of the existing solution is 0.75dB, and the insertion loss of the present invention is 0.45dB. The insertion loss of the present invention is reduced by 0.3dB. Figure 5 The isolation comparison when the path is disconnected is given. It can be seen from the figure that the isolation of the existing solution is -21.9dB, and the isolation of the present invention is 21.5-29dB. The worst point of the isolation performance is equivalent to the existing solution, and the best point is 7dB higher than the existing solution.

[0026] The present invention is based on the improvement of existing matching network devices to achieve path selection. Figure 2 The principle applies to the case where the resonant frequency of the matching components L1 and C1 is less than the operating frequency. If the resonant frequency of L1 and C1 is greater than the operating frequency (the operating frequency of the RF transceiver path), Figure 2 The schematic no longer applies. Figure 6 The schematic diagram applicable to this case is given. When the path is turned on Figure 6 The switch T1 in the circuit is turned on, while T2 and T3 are turned off (that is, the fifth switch is turned on, while the third and fourth switches are turned off); when the path is disconnected Figure 6 The switch T1 in the figure is turned off, and T2 and T3 are turned on (that is, the fifth switch is turned off, and the third and fourth switches are turned on). The equivalent schematic diagram is the same as Figure 3 (b) and (d) in are consistent. Figure 6 In the example, the equivalent capacitance Ce when the path is closed is the parallel connection of C2 and C1, which makes Ce larger than C1, thereby reducing the original parallel resonance frequency of L1 and C1 to the operating frequency.

[0027] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A matching network capable of realizing path selection, applied to a radio frequency transceiver path structure, characterized in that: It includes a matching unit, a resonance unit and a control unit; When the RF transceiver path needs to be turned on, the control unit controls the resonance unit not to work, and at the same time makes the matching unit play a matching role in the RF transceiver path, and the RF input signal is output after passing through the matching unit, so as to achieve the matching and conduction of the RF transceiver path; when the RF transceiver path needs to be disconnected, the control unit controls the resonance unit and the matching unit to generate parallel resonance, blocking the RF signal from passing, thereby achieving the path disconnection; The matching unit includes an inductor and a first capacitor; the resonance unit includes a second capacitor; When the resonant frequency of the inductor and the first capacitor is less than the operating frequency of the RF transceiver path, the control unit includes a first switch and a second switch; one end of the inductor is connected to one end of the second switch, and the other end of the inductor is connected to one end of the first capacitor; the other end of the first capacitor is connected to one end of the second capacitor and one end of the first switch, the other end of the first switch is grounded, and the other end of the second capacitor is connected to the other end of the second switch; When the resonant frequency of the inductor and the first capacitor is greater than the operating frequency of the RF transceiver path, the control unit includes third to fifth switches; one end of the inductor is connected to one end of the fifth switch, the other end of the inductor is connected to one end of the first capacitor and one end of the second capacitor, the other end of the first capacitor is connected to one end of the third switch and one end of the fourth switch, and one end of the fourth switch is also connected to the other end of the fifth switch; the other end of the third switch is grounded; and the other end of the fourth switch is connected to the other end of the second capacitor.

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