Integrated microwave terrestrial radio with dovetail attachment

- 28036 Madrid

IS 2 158 583 T3

DESCRIPTION

Integrated microwave terrestrial radio with dovetail joint.

The present invention relates to an integrated point-to-point microwave radio frequency unit, comprising a housing having a front face and a rear face, an electronic microwave radio frequency transceiver assembly within the housing, the electronic assembly having an external connection. and an antenna connection, an antenna fixed to the front face of the housing, a microwave radio frequency power supply that communicates between the antenna and the antenna connection of the microwave transceiver electronics assembly, a mounting structure having a mounting structure support element, and a housing support element fixed to the housing, the housing support member and the mounting structure support member being applicable to each other. Furthermore, the present invention relates to a method for mounting such a radio frequency unit.

A frequency unit and an antenna as outlined above are described in DE 27 24 130 A1. The frequency unit and the antenna are both provided in a single housing. The housing is mounted on a mast by means of brackets or arms. The rear side of the housing is provided with two L-shaped plates, each fixed to a U-shaped plate by screws. The U-shaped plate is connected to the modules with a pair of screws. In order to align the antenna with a remote or remote system, the frequency unit / antenna can be rotated around the mast by loosening the screws and can be tilted or oscillated around the axis by loosening the screws.

Document US 5,060,898 discloses a surface mounting bracket, comprising a body, which can optionally be glued on its rear face to fasten it to a flat wall surface by means of an adhesive bond, having a dovetail upper part. to support an object by means of a dovetail joint. The object which is mounted on the surface mounting bracket has a dovetail groove on the back, which dovetail groove has two facing, beveled side walls projecting respectively inwardly.

GB 2,207,557 A describes an antenna arrangement for a television that comprises an antenna and an amplifier housed in a box to provide a compact unit for use in areas of low signal intensity. The housing of the box comprises a base portion having a rear wall and a peripheral side wall. A rectangular recess is formed in a lower part of the rear wall to receive and mount an amplifier. A somewhat deeper recess was formed in a rear wall of the recess for the attachment of a mounting arm and mounting arm assembly. A third mounting assembly comprises an iron plate attached to a rectangular aluminum tube.

The plate was bolted to the central recess by bolts respectively extending through an open slot and a kidney-shaped slot in the plate. Both slits are provided to allow a certain adjustment of the position of the base part in relation to the plate.

WO 95/25387 describes a transceiver with an antenna, used for transmission and reception of radio signals. The transceiver / antenna unit was mounted on a mast by means of a U-shaped plate, both of whose arms are pivotally suspended on a support element fixed to the mast. The U-shaped plate allows the antenna / transceiver unit to tilt or swing in a vertical direction.

Generally microwave radio communications are widely used to transfer large amounts of data, such as in communications links over long microwave distances on the ground and in space. They are also interesting for lower-margin, lower-power applications such as basic voice, video, and data junctions between, for example, a cellular base station and a central telephone office. In such applications, the microwave transmission distance is typically about 910 to 9250 m, the microwave signal is at a specific frequency in the range of about 2 to 94 GHz, and the power output of the microwave transmitter is about 100 milliwatts. Such microwave communication systems are generally referred to as "point-to-point" systems.

Corresponding to high-power microwave communication systems, a traditional point-to-point system has three basic phase parts: a signal processing unit (SPU), sometimes referred to as an "indoor" unit that has the radio band components of base, a radio frequency (RF) unit (RFU), sometimes referred to as an “outdoor” unit that has the microwave radio frequency components, and an antenna. Because microwave power is required between the microwave frequency operating components, the radio frequency unit was located within a few meters of the antenna, which is currently mounted outside and facing another terminal point. a point located at a certain distance. The antenna is topically a "cassegrain" type parabolic antenna. The signal processing unit can be located at a certain distance from the radio frequency unit. A common coaxial cable assembly runs between the signal processing unit and the radio frequency unit, but a coaxial microwave power supply is required between the radio frequency unit and the antenna.

As point-to-point systems become increasingly popular, their physical integration becomes increasingly important. Existing radio frequency units and antennas are bulky, heavy, and, in many cases, difficult to mount, align, and keep in alignment. With the proliferation of point-to-point systems in large

ES 2 158 583 T3 cities, it is becoming increasingly difficult to find new mounting space on existing masts at any point. Installers must lift the last installed RF unit and antenna to ever more precarious positions in order to establish line of sight contact with the remote terminal. The radio frequency unit and the antenna must be mounted in close proximity to each other. Traditional mounting systems for the radio frequency unit and antenna include arm arrangements, bracing winds, and turnbuckles or turnstiles. Great care must be taken in aligning the antenna with a remote antenna by adjusting the mounting system. If the antenna must be replaced later, the new antenna must be re-aligned.

To solve these problems, the assignee of the present invention is developing an integrated point-to-point microwave radio frequency unit and antenna, which is much more compact and lighter in weight than traditional systems. However, there is the underlying problem of supporting the integrated unit in such a way as to make installation and replacement simple and convenient. There is a need for a mounting method or system to be used in conjunction with the improved integrated antenna and radio frequency unit that solves these problems. The present invention satisfies this need, and further provides advantages related to these problems.

Summary of the invention

The present invention, as defined in claim 1^to, provides an integrated point-to-point microwave radio frequency unit with a convenient support structure. The support structure allows the integrated radio frequency unit to be quickly and easily mounted on a structure such as a mast by one person. The support structure keeps the integrated RF unit in a stable fixed orientation after the alignment has been completed. If the integrated radio frequency unit needs to be replaced at a later time, it is easily removed and replaced by one person. The support structure ensures that the replacement unit will be oriented to the same remote terminal as the withdrawn unit, an important convenience because the difficulty and cost of realignment can be high. The supporting structure is light in weight and inexpensive.

According to the invention, as defined in claim 7^to, an integrated point-to-point microwave radio frequency unit is operable in conjunction with a mounting frame having a mounting frame reference flat surface and a mounting frame support member. The radio frequency unit comprises a housing having a front face and a rear face, the rear face having a housing reference plane surface therein. An electronic microwave radio frequency transceiver assembly, with an internal connection and an antenna connection, is inside the housing. An antenna is attached to the front face of the housing, and a microwave radio frequency feed communicates between the antenna and the antenna connection of the electronic microwave transceiver device. A housing support member is attached to the housing. The housing support element and the mounting structure support element are applicable to each other such that the flat reference surface of the housing is positioned in contact with the surface of the reference plane of the mounting structure in a relative relationship. face to face.

The contact reference planes provide a means of aligning the radio frequency unit. Once the bearing reference plane surface orientation is established during the initial alignment procedure, any subsequently installed radio frequency units are installed in an aligned condition or state.

The support element is preferably a dovetail structure in which one of the dovetail parts, preferably the male part, is fixed to the rear face of the housing. The other of the dovetail parts, preferably the female part in which the male part is slidably received, is fixed to the structure to which the integrated radio frequency unit is mounted. The two dovetail parts are held in a fixed relationship to each other by any convenient means, preferably a set screw. A bolt or lock may be provided to prevent theft of the integrated radio frequency unit.

The housing is installed by sliding the two parts of the support element together and tightening the set screw. The antenna is oriented to a remote terminal aligning the part of the support that is fixed to the structure. If at a later time the integrated radio frequency unit element must be replaced, the set screw is removed and the dovetail structure is separated by sliding the elements apart. A new integrated radio frequency unit is installed by sliding the dovetail elements together and tightening the set screw. The antenna of the integrated radio frequency unit is therefore aligned, because the two reference planes are held in a fixed region relative to each other.

Although this procedure may seem fairly straightforward when described, it must be remembered that replacement is often performed in a precarious position and under difficult circumstances such as high altitude above the ground, strong wind, and significant personnel exposure. When considered in light of these conditions, the present attempt provides great advantage by reducing the weight that must be carried by the technician, and by simplifying installation, alignment, and replacement procedures compared to previous attempts.

Other features and advantages of the present invention will become apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles

ES 2 of the invention. The scope of the invention is not, however, limited to this preferred embodiment. Brief description of the drawings

Fig. 1 is a schematic diagram of a microwave radio transmitter and receiver;

Fig. 2 is a perspective view of a traditional antenna and microwave radio frequency unit;

Fig. 3A is a front perspective view of an integrated radio frequency unit / antenna according to the invention;

Fig. 3B is a rear perspective view of the integrated radio frequency unit / antenna of FIG. 3A;

Fig. 4 is an enlarged schematic sectional elevation view of a detail of the support structure of the integrated radio frequency unit / antenna of FIG. 3B, taken generally at a position along lines 4-4;

Fig. 5 is a view similar to that of FIG. 4, but in a different vertical position illustrating a set screw for holding the male and female dovetail elements in a fixed relationship;

Fig. 6 is a view similar to that of FIG. 5, illustrating another arrangement of the adjusting screw;

Fig. 7 is a view similar to that of FIG. 4, but still in a different vertical position illustrating a latch shape;

fig. 8 is a sectional view taken along lines 8-8 of FIG. 4, illustrating another locking system;

Fig. 9 is a schematic perspective view of a traditional antenna and radio frequency unit and an integrated radio frequency unit / antenna mounted on a mast; Y

Fig. 10 is a block flow diagram for a method using the mounting system according to the invention.

Detailed description of the invention

Fig. 1 is a schematic diagram of a microwave radio transceiver system 20. The general electronic structure of such systems 20 is known in the art and is described in greater detail for example in "RF Components for PCS Base Stations", published by Strategies Unlimited, 1996. The present invention is not based on a change from this known basic electronic system, but on its integration and assembly in a very advantageous way.

The system 20 includes a signal processing unit 22 (sometimes referred to as an "indoor unit") that processes baseband signals, a radio frequency unit 24 (sometimes referred to as an "outdoor unit") that processes microwave signals, and a microwave antenna 26. The signal processing unit has an input / output 28 for voice, video and / or data binding information. This input / output 28 is handled by baseband circuits 30 and a modulator / demodulator 32. A controller 34 and a power supply 36 are also provided in the signal processing unit 22. The signal processing unit 22 communicates with the radio frequency unit 24 at low frequencies via a traditional coaxial signal cable 38.

583 T3 6

The radio frequency unit 24 includes a microwave transceiver 40 that operates in a selected microwave frequency band within the broad band extending from about 2 to about 94 GHz by converting the low frequency signal from the signal processing unit 22 . A controller 42 and a power supply 44 are provided in the radio frequency unit 24. Microwave transceiver 40 has an antenna connection 46 to which a microwave radio frequency feed 48 is connected to provide a signal to antenna 26 or to receive a signal from the antenna. The microwave radio frequency feed 48 may be a coaxial cable or waveguide that cannot be more than a few meters in length without undergoing substantial signal attenuation.

Fig. 2 represents the implementation of a traditional anterior radio frequency unit 24 and antenna 26, connected by a microwave power supply 48, using the electronic device of FIG. 1. Radio frequency unit 24 topically measures 305 by 305 by 305 mm and weighs approximately 15.75 kg. Antenna 26 is a parabolic antenna having a dish diameter of approximately 305 mm or more and a weight of approximately 6.75 Kg. Both components must be mounted in a position such that antenna 26 can be oriented to a similar terminal but located far apart. The installer must find a means to mount the antenna 26 so that it is aligned with the antenna of the remote unit, and to mount the radio frequency unit 24 so that it is secure even though it is within the range allowed by the length of the power supply 48. of microwave. Other versions of the prior system of fig. two in which the paraboolic antenna was fixed directly to the radio frequency unit, but such a combined system is still difficult to handle and heavy.

Figs. 3A and 3B show an integrated radio frequency unit / antenna of the invention in front and rear perspective views. This apparatus uses the general electronic assemblies of fig. 1, but with a different architecture and a different antenna that offer significant advantages. An integrated radio frequency unit / antenna 60 includes a housing 62 having an outer wall 64 with a front face 64a and a rear face 64b. A handle 65, which may be in one piece or detachable, extends from the housing 62 and allows the radio frequency unit / antenna 60 to be easily carried. An electronic (not visible) microwave radio frequency transceiver assembly is secured within housing 62. The electronic assembly includes microwave transceiver 40, controller 42, and power supply 44. Part of the outer wall 64, in this case the front face 64a includes an integrated planar antenna 68. The planar antenna 68 may be formed separately and attached to the wall 64, as illustrated, or it may be formed in one piece as part. from the wall itself. That part of wall 64 that is not antenna 68 can be made of any operable material, such as

ES 2 158 583 T3 as metal or plastic. An aerodynamic dome (not shown) in the form of a plastic sheet may be mounted on the face of the flat antenna 68 to protect it. Planar antenna 68 is preferably a continuous short transverse antenna (CTS). The CTS microwave antenna is known in the art and is described, for example, in US Patent No. 5,266,961, the disclosure of which is incorporated herein by reference.

The integrated radio frequency unit / antenna 60 has an antenna connection and a microwave radio frequency feed wire that runs from the antenna connection to the rear side of the flat antenna 68. The radio frequency feed is at least 25 to 50 mm long and is fully contained within housing 62, and is consequently not visible in FIGS. 3A and 3B. There is very little microwave attenuation when the signal passes through this short feed. The installer is only required to position and fix the single integrated radio frequency unit / antenna 60 in place, and is not concerned with moving and positioning the two units in a compatible manner.

Fig. 3B illustrates a portion of a support member 70 whereby the housing 64 and attached components can be mounted to a mounting structure. Support member 70 includes a raised portion of housing 64 in the form of a cap section 72 extending rearwardly from rear face 64b. Attached to the cap section 72 and extending further atreas therefrom is a first part of the support member 70, illustrated as a preferred male dovetail fitting or hardware 74. The male dovetail fitting 74 includes a relatively narrow base 76 and a laterally enlarged protrusion 78.

Fig. 4 illustrates the support member 70 in greater detail, both with the first part, as previously described, and with a second part shown. The second preferred part is a female dovetail fitting 80 having a mortise or notch 82 that slidably receives the projecting portion 78 of the male dovetail fitting 74 therein. (In figs. 4 to 8, the clearance between the protrusion and the mortise is exaggerated so that it is visible). The female dovetail fitting 80 is attached to a frame (not shown here, but will be described in relation to FIG. 9). Equivalently, the female dovetail fitting can be attached to the housing and the male dovetail fitting attached to the frame.

Cap section 72 has an air-facing face that defines a housing reference plane surface 83a. The female dovetail fitting 80 has a forward-facing face that defines a mounting structure datum plane surface 83b. When the support members in the form of the male dovetail fitting 74 and the female dovetail fitting 80 are slidably engaged with each other, the reference plane surfaces 83a and 83b are in facing relationship with each other. When the application between the support elements is complete, the two surfaces 83a and

83b of the datum plane are attracted to face-to-face contact.

Contact between the two flat surfaces reliably and reproducibly establishes the angular orientation of the radio frequency unit / antenna 60. The dovetail or other type of support element between the radio frequency unit / antenna 60 and the mounting structure does not inherently produce a highly reproducible angular orientation, due to the tolerances required when two elements must be able to be mounted together under adverse conditions. . That is, if the dovetail portions have tolerances large enough to make sliding together and apart easy enough to be useful, the resulting angular tolerances are unacceptably large. For example, the current radio frequency unit / antenna 60 is to be reproducibly alignable to a range of 1/4^°. The inherent tolerances in the dovetail support member do not, by themselves, allow this degree of reproducibility.

The contact of the reference plane surfaces 83a and 83b establishes a very precise and repeatable angular orientation for the radio frequency unit / antenna 60. In the preferred embodiment, the contact length of surfaces 83a and 83b is approximately 100mm. Controlling the angular orientation of surfaces 83a and 83b to limits of approximately 0.381mm over that 100mm distance during manufacturing results in the precision and repeatability required for the orientation between the two reference plane surfaces 83a and 83b. Placing the housing reference plane 83a over cap section 72 positions it further from the centerline of the radio frequency unit / antenna 60, allowing greater tolerances in the orientation and flatness of the reference plane surfaces 83a and 83b. . This care to achieve the greatest possible manufacturing tolerances, while ensuring that the angularity specification has been met, is important in view of the way in which the radio frequency unit / antenna 60 is used, as it is to be described. subsequently. If an already aligned radio frequency unit / antenna is removed and replaced, the replacement unit will be aligned to the specification with a 1/4 margin.^° if its reference plane surface 83a satisfies the plane orientation tolerance described above. The higher that tolerance, the easier it is to satisfy commercial scale manufacturing operations.

After the male dovetail fitting 74 is slidably engaged with the female dovetail fitting 80, the relative positions of the two are fixed. The preferred system for setting relative positions, as shown in FIGS. 5 and 6, is with a set screw 84 that extends through a threaded shaft in the female dovetail fitting 80. There may be provided when one or more adjusting screws 84 are needed. When the set screw 84 is tightened, one end 86 of the

ES 2 158 583 T3 adjusting screw abuts protruding portion 78 and fixes the position of accessories 74 and 80. Adjusting screw 84 is loosened and removed to allow two accessories 74 and 80 to be disengaged. Set screw 84 may be positioned to be approximately perpendicular to the side face of the shanks with the head of set screw 84 in a recess 88 in female dovetail fitting 80, as shown in Fig. fig. 5. It may instead be positioned to lie parallel to the top of the protrusion with its head against the side of the female dovetail fitting 80, as shown in FIG. 6. End 86 of screw 84 may abut directly against the side of protruding portion 78 when tightened, as shown in FIG. 5, or it may abut against a vane 90 that distributes the axial load of the set screw 84 on the side of the projecting portion, as shown in FIG. 6. Any of the systems of FIGS. 5 and 6 can be used with or without the oalabe.

In the embodiments of FIGS. 4 and 5, the base 76 of the male dovetail fitting is permanently attached to the cap section 72 and thus to the rear face 64b of the housing 62. In another embodiment illustrated in FIG. 6, the base 76 may be removably attached to the rear face 64b with screws 92 that extend through the base 76 and the protrusion 78 or other operable fasteners.

The adjusting screw 84 fixes the positions of the two accessories 74 and 80 relative to each other. The two accessories 74 and 80 can also be locked together to prevent movement of the integrated outdoor unit / antenna 60. In one system, as illustrated in FIG. 7, names 94a and 94b extend through male dovetail fitting 74 and female dovetail fitting 80, respectively, in an axially aligned relationship, forming a continuous name 94 therethrough. The animator 94 was positioned in a different position along the length of the fittings 74 and 80 than the locking screw 84 so that there is no interference between the two. A locking element 96, which may be, for example, a pin with bolts at both ends, a strap whose ends lock together, or an elongated padlock, is placed through the body 94 to lock the accessories 74 and 80 together.

Fig. 8 illustrates another locking system. A lug 120 is attached to one end of the projecting portion 78, and a plate 122 with an opening 124 therethrough is attached to the corresponding end of the female dovetail fitting 80. Plate 122 has an opening 124 therethrough, and tab 120 fits through opening 124 when dovetail fittings 74 and 80 are engaged together in the installed position. Lug 120 has an anim 126 through it, which receives a padlock or other locking element through it (not shown). The two dovetail accessories 74 and 80 are therefore easily locked together with a standard padlock.

Fig. 9 which is schematic and not drawn to scale, illustrates the mounting of a traditional frequency unit 100 and its antenna 102, connected by its microwave power supply 104, on a mast 106. The antenna 102 was fixed to the mast by a combination of modules , struts, and winds (collectively, bracket 108) whose positions can be adjusted by turnstiles, set screws, or the like. The alignment is relatively difficult. The support system does not allow easy locking of the antenna to the mast, as with the current system. Also, if the antenna must be replaced for any reason, the support structure must be disassembled to such an extent that a complete realignment of the replacement antenna is usually necessary.

Also shown in fig. 9 there is an integrated radio frequency unit / antenna 60 of the invention and its bracket 70, and FIG. 10 illustrates a preferred use of the structure. The mounting structure was provided, number 130, and the radio frequency unit / antenna 60 was provided, number 132. The female dovetail fitting 180 is attached to the mounting mast 106 using an angularly adjustable arm 110 or other support member whose angular position is adjustable during alignment of the antenna toward the remote antenna. Male dovetail fitting 74 is applied to female dovetail fitting 80 in the correct position and set screw 84 is tightened, number 134. The radio frequency unit / antenna 60 is aligned with the corresponding remote unit by changing the angular position of the arm 110 until the transmitted signal intensity between the two antennas is maximized, number 136. The initial alignment of the radio frequency unit / antenna 60 can considered as establishing the angular orientation of the reference plane 83b which is not changed thereafter.

If the integrated radio frequency unit / antenna 60 is to be replaced later, the bolt (if any) is removed, the set screw is loosened, and the dovetail accessories 74 and 80 are slidably disengaged, number 138. A new integrated radio frequency unit / antenna 60 is provided and installed, number 140, slidably applying its dovetail fitting 74 to the dovetail fitting 80 whose position has not been changed by the removal of the old radio frequency unit / antenna. 60, adjusting the set screw, and reinstalling the bolt (if any). During this installation, the reference plane surface 83a of the replacement unit is brought into intimate contact with the reference plane surface 83b, which was already aligned relative to the remote or remote terminal. Realignment of the replacement radio frequency unit / antenna is therefore not topically required. In contrast to replace the traditional antenna 100, the support structure 108 must be disassembled and replaced, and the entire antenna must be realigned.

The support system of the invention has been scaled down to practice with a prototype integrated radio frequency unit / antenna 60 for operation at a microwave frequency of 37-40 GHz as shown in FIG. 3A. The flat antenna has a width W of about 6

ES 2 158 583 T3 is approximately 266.7 mm, a length L of approximately 266.7 mm, and a thickness T of approximately 25.4 mm. The remaining components, microwave transceiver 40, controller, and power supply 44 fit into a housing that is the same length and width, and a thickness T of approximately 50.8mm. The overall size of the housing and antenna assembly is approximately 305mm by 305mm by 76.2mm. The weight of the integrated radio frequency unit / antenna 60 is approximately 5.85 kg. It is highly desirable that this weight be less than approximately 6.75 kg, since higher weights are much more difficult for personnel to transport to positions. mounting exposed. The bracket system described here is totally satisfactory for mounting this device.