CN203288755U - RoF-type phase control active integrated antenna array suitable for FDD system - Google Patents

Abstract

The utility model discloses a RoF phase-controlled active integrated antenna array suitable for FDD systems, which includes an optical module, an intermediate frequency transceiver module, a radio frequency transceiver module and an antenna unit; The module is connected with multiple radio frequency transceiver modules, and each radio frequency transceiver module is connected with an antenna unit. Different from the traditional array antenna, each antenna unit in the active integrated antenna array of the utility model is directly connected to a complete radio frequency transceiver module, and the signals of each unit are divided/combined at the intermediate frequency, and passed through The intermediate frequency transceiver module is connected with the optical module after processing, and finally the signal can be converted into an optical signal by the optical module for long-distance low-loss transmission; the phase of the RF transceiver module behind each antenna unit is controllable, so that the beam of the entire array is in Scanning is possible in the vertical direction.

Description

RoF phased active integrated antenna array for FDD system

technical field

The utility model relates to an active antenna, in particular to an RoF phase-controlled active integrated antenna array suitable for FDD (Frequency Division Duplexing, frequency division duplexing) systems. the

Background technique

Antennas are one of the key components of various wireless communication systems. The main technical indicators to measure their pros and cons are: impedance bandwidth, beam width, sidelobe level, gain and efficiency, etc. The conductor loss, dielectric loss of the antenna radiating unit, the insertion loss of the feeding network and the loss of the feeder will greatly reduce the efficiency of the entire system, resulting in a considerable proportion of the transmitter power being dissipated by the antenna and the feeder, and seriously affecting the receiving sensitivity. Therefore, high efficiency and intelligence have become the research goals of the next generation of wireless communication antennas. the

A traditional cellular mobile communication base station is mainly composed of an antenna, a feeder cable and a radio frequency transceiver. The antenna on the top of the tower is connected to the transceiver below through a certain length of feeder cable. For the downlink, the output power of the RF transmitter is fed into the antenna installed on the top of the tower through the feeder cable and transmitted into the air; for the uplink, the mobile phone signal is received by the base station antenna on the top of the tower and enters the RF receiver under the tower through the feeder cable . Most traditional base station antennas use directional antennas with sectoral radiation patterns. The beamwidth in the horizontal plane is generally 120 degrees (10dB beamwidth), and the gain is generally about 14.5dBi. Such an antenna generally consists of an array of 8 to 12 elements in the vertical direction. The conductor loss, dielectric loss of the antenna radiating unit, the insertion loss of the feed network and the loss of the feeder will greatly reduce the efficiency of the antenna feeder system, resulting in a considerable proportion of the transmitter power being dissipated by the antenna and the feeder, and seriously affecting the receiving sensitivity . The antenna efficiency does not take into account the loss of the feeder cable. Obviously, for the above-mentioned base stations, it is more suitable to describe and

${\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; AF</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}}{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}}$

Analyze the performance of wireless communication systems. To this end, we define the antenna feed efficiency as follows

In the formula, _EAF represents the efficiency of antenna feeder (Efficiency of Antenna and Feeding Cable), P _e refers to the effective radiation power actually radiated into the air, and P _t refers to the output power of the RF transmitter.

For traditional base stations and base station sector antennas, the feeder length can usually reach tens of meters, and the loss can reach 3dB or even greater; the loss of the internal feed network of the sector antenna is usually about 1 to 2dB. In contrast, the conductor loss, dielectric loss and reflection loss of the radiating unit are much smaller when they are well matched. Therefore, less than half of the power output from the RF transmitter is radiated, that is, the antenna feed efficiency E _AF <50% at this time. We know that if the output power of the RF transmitter is doubled while ensuring the linearity, its cost will increase by 0.8 to 1 times, and its DC power consumption will increase by 1 to 1.2 times.

Therefore, it is extremely urgent to research and realize new antenna technologies with high efficiency, beam controllability, low power consumption, low cost, and various excellent characteristics that support RoF (Radio over Fiber, wireless communication over light). the

Utility model content

Purpose of the utility model: In view of the problems and deficiencies in the above-mentioned prior art, the purpose of the utility model is to provide a RoF phase-controlled active integrated antenna array suitable for the FDD system, so that the transmitting channel and the receiving channel in the vertical plane The beam pointing of the channel is independently controllable, which is highly efficient and energy-saving. the

Technical solution: In order to achieve the purpose of the above-mentioned utility model, the technical solution adopted in the utility model is a RoF phase-controlled active integrated antenna array suitable for FDD systems, which includes an optical module, an intermediate frequency transceiver module, a radio frequency transceiver module and an antenna unit; the optical module connected to the near-end machine is connected to multiple radio frequency transceiver modules through the intermediate frequency transceiver module, and each radio frequency transceiver module is connected to an antenna unit. the

Wherein, the intermediate frequency transceiver module includes a transmitting module connected to the optical module, and the transmitting module is connected to the input terminal of the intermediate frequency power splitter; the intermediate frequency transceiver module also includes a receiving module connected to the optical module, and the receiving module is connected to the intermediate frequency combiner. The output end is connected; the output end of the intermediate frequency power divider is connected to the feed port of the antenna unit through the radio frequency transceiver module; the feed port of the antenna unit is also connected to the input end of the intermediate frequency combiner through the radio frequency transceiver module . the

Wherein, the radio frequency transceiver module includes a first mixer, a first phase shifter, an amplifier and a duplexer which are sequentially connected to the intermediate frequency power divider, and the other end of the duplexer is connected to the feed port of the antenna unit; The feeding port of the antenna unit is also sequentially connected to the radio frequency receiving module, the second phase shifter and the second mixer through the duplexer, and the second mixer is connected to the input end of the intermediate frequency combiner. the

The RoF phase-controlled active integrated antenna array suitable for FDD systems of the present utility model includes an antenna unit, a radio frequency transceiver, a phase shifter, a mixer, an intermediate frequency transceiver and an optical module, wherein the intermediate frequency transceiver module includes an intermediate frequency power divider / combiner and amplifying circuit part; different from the traditional array antenna, each antenna unit in the active integrated antenna array in the utility model is directly connected with a complete radio frequency transceiver module, and the signals of each unit are in the intermediate frequency The power splitting/combining is completed on the top, and then connected to the optical module after passing through the intermediate frequency transceiver module. Finally, the signal can be converted into an optical signal through the optical module for long-distance low-loss transmission. The phase of the RF transceiver module behind each antenna unit is controllable, so that the beam of the entire array can be scanned in the vertical direction. the

Beneficial effect: the utility model has the following advantages:

1:) It has high antenna feed efficiency, which can reach 80% to 90%. After adopting the design of active integrated antenna array, the RF transceiver module is directly connected to the antenna unit through the connector, which avoids the loss caused by the feeder cable in the traditional RRU+passive antenna array solution, and because the power splitting/combining network is Completed at the intermediate frequency, compared with the RF power splitting/combining network of the passive antenna array, the loss will be further reduced, the overall loss can be controlled within 1dB, and the antenna feed efficiency of the system can reach 80% to 90%. the

2:) The beams of the transmitting and receiving channels in the vertical plane can be scanned independently, and the beams can point to any direction within the range of ±40°. Compared with the traditional RRU (Radio Remote Unit, radio frequency remote unit), the radio frequency transceiver module of this solution adds a high-precision and low-loss numerical control phase shifter to each channel. Through the control of the phase shifter, the antenna array can be set The phase of each unit, setting the phase of each antenna unit at an appropriate value can control the beam of the entire antenna array to point to the desired direction, so as to realize the beam scanning of the array beam in the vertical plane. Because the phase shifters of the receiving and transmitting channels in the RF transceiver module are independently controllable, the receiving and transmitting beams of the system are also independently controllable. the

3) Thanks to the controllable beam pointing of the antenna array, when one or several channels in the antenna array fail, the phase of the remaining channels can be adjusted to adjust the radiation beam pointing of the antenna array, which can compensate for the failure of the channel. The change of the radiation direction of the incoming antenna enhances the stability of the system to a certain extent. the

4) Using RoF, low-loss transmission is possible, and networking is convenient. the

Description of drawings

Fig. 1 is the structure schematic diagram of the RoF type phase control active integrated antenna array applicable to the FDD system of the present invention;

Fig. 2 is the beam scanning of the receiving channel of the antenna of the present invention (with 10° as the interval, the beam pointing can be customized);

Fig. 3 is the beam scanning of the transmitting channel of the antenna of the present invention (at intervals of 10°, the beam pointing can be customized). the

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment, further set forth the utility model, should be understood that these embodiments are only used for illustrating the utility model and are not intended to limit the scope of the utility model, after having read the utility model, those skilled in the art will understand this utility model The modifications of various equivalent forms of the utility model all fall within the scope defined by the appended claims of the present application. the

As shown in Figure 1, a RoF phase-controlled active integrated antenna array suitable for FDD systems of the present invention includes an optical module 1, an intermediate frequency transceiver module 2, a radio frequency transceiver module 3 and an antenna unit 4; The optical module 1 connected to the machine is connected to several radio frequency transceiver modules 3 through the intermediate frequency transceiver module 2, and each radio frequency transceiver module 3 is connected to an antenna unit 4. The power supply supplies power to the entire ROF phase-controlled active integrated antenna, and the optical module 1 is connected to the optical module of the near-end device through an optical fiber. the

The function of the optical module 1 is photoelectric conversion, the sending end converts the electrical signal into an optical signal; after being transmitted through the optical fiber, the receiving end converts the optical signal into an electrical signal. the

The transmitting module 21 in the intermediate frequency transceiver module 2 processes the signal transmitted from the optical module 1, and then transmits it to each radio frequency transmitting channel through the intermediate frequency power divider 22; For the signals sent from each channel of the module 3 , the IF combiner 24 synthesizes the signals into one signal and performs subsequent processing, and then is further processed by the receiving module 23 and then transmitted to the optical module 1 . the

The radio frequency transceiver module 3 is the core part of the active integrated antenna array. The transmitting part up-converts the intermediate frequency signal transmitted by the intermediate frequency power divider 22 to the radio frequency frequency, performs filtering, phase shifting and amplification, and then transmits it to the antenna unit 4; The receiving module 37 filters and amplifies the weak signal transmitted by the antenna unit 4 , and down-converts the signal to an intermediate frequency, and then the signals of each channel are combined in the intermediate frequency combiner 24 . the

The antenna unit 4 is an energy conversion device, which converts the signal generated by the radio frequency transmitting module 3 into electromagnetic waves and transmits them to the space, and collects the electromagnetic waves in the space and converts them into radio frequency signals and transmits them to the radio frequency receiving module 3 . the

Wherein, the intermediate frequency transceiver module 2 includes a transmitting module 21 connected to the optical module 1, and the transmitting module 21 is connected to the input end of the intermediate frequency power divider 22; the intermediate frequency transceiver module 2 also includes a receiving module 23 connected to the optical module 1, The receiving module 23 is connected to the output terminal of the IF combiner 24 . the

Described radio frequency transceiving module 3 comprises first mixer 31, first phase shifter 32, amplifier 33, duplexer 34 that are connected to intermediate frequency power divider 22 in turn; The feed port of the antenna unit 4 is also connected to the radio frequency receiving module 37, the second phase shifter 36, and the second mixer 35 in sequence through the duplexer 34, and the second mixer 35 is combined with the intermediate frequency The input terminal of the device 24 is connected. First mixer 31, first phase shifter 32, amplifier 33, duplexer 34 constitute the transmitting part of radio frequency transceiver module 3, second mixer 35, second phase shifter 36, radio frequency receiving module 37 and The duplexer 34 constitutes the receiving part of the radio frequency transceiver module 3 . the

The output end of the intermediate frequency power divider 22 is connected to the feed port of the antenna unit 4 through the radio frequency transceiver module 3; the feed port of the antenna unit 4 is connected to the input end of the intermediate frequency combiner 24 through the radio frequency transceiver module 3. the

The radio frequency transceiver module 3 can control the phase of each channel in the antenna array through the phase shifter. Setting the phase of each channel at a suitable value can control the beam of the entire antenna array to point to the desired direction, thereby realizing beam scanning in the vertical plane . the

Each antenna unit 4 of the utility model is directly connected with an independent radio frequency transceiver module 3. Compared with the traditional RRU (radio frequency remote module) + passive antenna array, it can ensure the EIRP (effective full Under the same conditions, the RF output power required by a single RF transmitting module in this solution is only 1/N of the output power of the power amplifier in the traditional RRU solution (N is the number of antenna arrays, generally 8-12) , so that small and medium-sized power amplifiers can be used to replace high-power amplifiers in ordinary RRU solutions, which reduces the system’s heat dissipation requirements, and can further reduce system cost and circuit area; In the system, the requirement on the power capacity of the duplexer can be reduced, further reducing the cost and volume of the system. the

Compared with the traditional RRU, each channel of the radio frequency transceiver module of the present invention adds a digitally controlled phase shifter, through the control of the phase shifter, the phase of each unit in the antenna array can be set, and the phase of each antenna unit Setting an appropriate value can control the beam of the entire antenna array to point to the required direction, so as to realize the beam scanning of the array beam in the vertical plane. the

The phase of the radio frequency transceiver module 3 of the RoF phase-controlled active integrated antenna array of the utility model can be controlled, and by setting a specific phase, the beam of the array in the vertical plane can be directed to a required angle to realize the beam scanning function. The radio frequency transceiver module 3 is directly connected to the antenna unit 4 through a connector, which reduces the loss of the feeder line and the feeder network, and improves the efficiency of the antenna feeder. the

The antenna of an embodiment of the present invention is further described below. The antenna of this embodiment is a RoF type phase control active integrated antenna suitable for WCDMA systems. 1980MHz, the system works in FDD mode, the transceiver channels are isolated by duplexers, the array is a linear array with 8 units evenly distributed, the maximum transmit power of each radio frequency unit is 21dBm, the gain of the antenna unit is 7dB, and the maximum EIRP of the entire array is 45.5 dBm (0.5dB loss). The radiation beam of the array has a 3dB beamwidth of 10° in the vertical plane and can be directed at any angle within the range of ±40°. the

Fig. 2 and Fig. 3 are the beam scanning results of the antenna of the present utility model, with 10° as the interval during measurement, it can actually point to any angle, as can be seen from the test results, the beam scanning of the transmitting and receiving channels can be in the range of ±40° Point to exactly the desired location. the

Figures 2 and 3 show the beam scanning results of the active antenna of the embodiment in the transmitting and receiving states. It can be seen from the results that the beam of the active integrated antenna array can be adjusted in the vertical plane according to the needs of the system. When the antenna of this embodiment is used as a base station antenna system for mobile communications, the direction of the beam can be adjusted in time according to business needs to obtain optimal coverage; and thanks to the controllable characteristics of the beam direction of the antenna array, when the antenna array of this embodiment When one or several channels fail, the phase of the remaining channels can be adjusted to adjust the beam direction of the antenna array to compensate for the change of the antenna radiation direction caused by the channel failure, which enhances the stability of the system to a certain extent. the

Claims (3)

1. A RoF phase-controlled active integrated antenna array suitable for FDD systems, characterized in that it includes an optical module (1), an intermediate frequency transceiver module (2), a radio frequency transceiver module (3) and an antenna unit (4 ); the optical module (1) connected to the near-end machine is connected to multiple radio frequency transceiver modules (3) through the intermediate frequency transceiver module (2), and each radio frequency transceiver module (3) is connected to an antenna unit (4). 2. The RoF phase-controlled active integrated antenna array suitable for FDD systems according to claim 1, characterized in that: the intermediate frequency transceiver module (2) includes a transmitting module (21) connected to the optical module (1) ), the transmitting module (21) is connected to the input end of the intermediate frequency power divider (22); the intermediate frequency transceiver module (2) also includes a receiving module (23) connected to the optical module (1), and the receiving module (23) is combined with the intermediate frequency The output end of circuit device (24) is connected; The output end of the intermediate frequency power divider (22) is connected to the feed port of the antenna unit (4) through the radio frequency transceiver module (3); the feed port of the antenna unit (4) is also connected through the radio frequency transceiver module ( 3) Connect with the input terminal of the intermediate frequency combiner (24). 3. The RoF phased active integrated antenna array suitable for FDD systems according to claim 2, characterized in that: the radio frequency transceiver module (3) includes a first A mixer (31), a first phase shifter (32), an amplifier (33) and a duplexer (34), the other end of the duplexer (34) is connected to the feeding port of the antenna unit (4); The feeding port of the antenna unit (4) is also sequentially connected to the radio frequency receiving module (37), the second phase shifter (36) and the second mixer (35) through the duplexer (34), and the second mixer ( 35) is also connected with the input terminal of the intermediate frequency combiner (24).

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