WO2001097337A1

WO2001097337A1 - Connector

Info

Publication number: WO2001097337A1
Application number: PCT/FI2001/000561
Authority: WO
Inventors: Markku Pirinen
Original assignee: Valtimo Components Oy
Priority date: 2000-06-16
Filing date: 2001-06-14
Publication date: 2001-12-20
Also published as: FI108175B; AU2001267603A1; FI20001444A0

Abstract

The subject of the invention is a coupler, which includes a frame (1) with a fixing part (2, 11, 12) a low pass filter (3, 4, 5) and one or several coupler heads (9). Characteristic to a coupler according to the invention is that there is at least one conductor (4) insulated from the frame and functioning as a coil in the coupler, and that there is one or several capacitors (3, 5) at least in one end of the conductor.

Description

CONNECTOR

The subject of the invention is a coupler, which consists of a frame with a fixing part, a low pass filter and one or several coupler heads.

As wireless cornmunication has extremely increased various frequency bands from the frequency spectrum are occupied for civil use, for authorities as well as for military use. Because of the congestion in the use of the spectrum it is essential that various communication networks don't interfere with each others receiving and transmitting actions. Therefore various communication networks have exactly marked frequency ranges.

Various transmitting devices used in communication networks transmit not only the actual transmitting frequency but also injurious harmonic multiples of the transmitting frequency. As a duplex-filter fixed in front of the antenna, for example, cannot prevent the frequencies higher than some earlier mentioned transmitting and receiving frequencies been transmitted to air and receiving devices it is essential to use also low pass filters to eliminate the frequencies differing from the marked frequency band.

Present low pass filters are carried out as separate components or integrated, for example, inside the duplex-filter. The size of the devices has become remarkable smaller during the past ten years due to the fast development on the field. At the same time requirements to the functioning of filters have increased. As present low pass filters have been constructed in a technique requiring relatively much space it causes many difficulties to match them with modern devices, for example, limiting the design of the products and increasing manufacturing costs. Separate low pass filters present in use are mostly of unique design and manufacture for every application being different for various products. Various solutions always function in some what different way which causes problems, for example, in tuning.

The purpose of this invention is to provide a coupler with which the problems caused by the use of present technique mentioned earlier are prevented. Furthermore, the purpose of the invention is to provide a coupler of small size, but exactly repeatable by its electrical functioning thus decreasing the need of expensive tuning.

The purpose of the invention is achieved by the coupler which possesses the characteristics presented in the appended claim. Characteristic to the coupler according to the invention is that there is at least one conductor functioning as a coil and insulated from the frame in the coupler and that at least in one end of the conductor there is one or several capacitors. A coupler constructed in a such way includes a low pass filter which is of small size, of simple construction as well as electrically reliably functioning and exactly repeatable.

In the advantageous application according to the invention there is gaseous insulating material, like air, between the conductor and the frame. The use of such insulating material around the conductor functioning as a coil is a simple and functionally advantageous solution as well as technically advantageous to manufacture.

In the second advantageous application of the invention there is some electrical insulating material between the capacitors and the frame. By choosing an electrical insulating material and thus its properties (dielectric constant) suitably the capacitors of the condenser inside a frame of certain size may be matched with a certain frequency range of a communication network in a suitable way.

In the third advantageous application of the invention there are locking elements between the frame and electrical insulating material to lock electrical insulating material and the capacitor in the place. By means of locking elements insulating material is tightly situated against the capacitor and the frame, and thus mechanically firm and functionally stable coupler is achieved by a simple construction.

In the fourth advantageous application of the invention there is a conductor head in the other end of the coupler in order to connect the conductor to the coupler. The conductor head is a simple and reliably functioning part of the coupler in order to connect the coupler, for example, to a device inside a device casing.

In the fifth advantageous application of the invention there is a coupler head in the other end of the coupler in order to connect the coupler to another coupler or conductor. The coupler head is a simple and advantageous part of the coupler in order to connect and fix the coupler removable to another coupler or conductor.

In the sixth advantageous application of the invention the best return attenuation of the pass band has been adjusted to cover the frequency range of one or more communication networks, like that of a mobile network. When the return attenuation has been adjusted to cover frequency range of one or more communication networks the frequency range to go through the filter may be marked exactly in a reliable and suitable way.

In the seventh advantageous application of the invention the stop attenuation of the low pass filter has been adjusted to prevent the pass of frequencies higher than frequencies of communication networks. By means of suitable adjusted stop attenuation the access of harmonic multiples of higher frequencies can be prevented effectively and advantageously.

In the following, the invention is defined in more detail with reference to the attached illustrations, in which:

Figure 1 demonstrates a coupler according to the invention viewed from the side, and

Figure 2 demonstrates the scheme of the pass attenuation and return attenuation curve of a pair of couplers according to figure 1.

In the application of the coupler according to figure there is a frame 1, fixing part consisting of threads 2 and 12 and of flange 11, a low pass filter consisting of capacitors 3 and 5 and of conductor 4, air 6 as gaseous insulating material between the conductor and the frame, electrical insulating material 7 between the capacitors and the frame and locking elements 8 of the insulating material. Furthermore, there is a coupler head in one end of the frame 1 and a conductor head 10 in the other end of the frame 1.

In the application according to figure 1 the frame 1 is a cylindrical object made of brass. The inner cylindrical space of the frame is machined to spaces of various size. The outer surfaces are mainly threaded (threads 2 and 12) except for the flange 11, against which the coupler is meant to be fixed to its target place. The thread 2 is there for the fixing of the coupler head or another coupler. Accordingly the thread 12 is there for the fixing the coupler to the casting or to another object.

The capacitor 3 placed in the end of the coupler end 9 is situated between the electrical insulating material 7 and the frame. In the application according to figure 1 electrical insulating material is PTFE plastic. The other capacitor 5 adjusted to the other end of the frame (the end of the conductor end) is of the same kind as the earlier mentioned capacitor 3 except for the fact that the electrical insulating material there has been fixed to the frame by means of locking plates 8 made of brass on the both sides of the insulating material. In the application according to figure 1 the capacitors 3 and 5 include capacitor plates. The coupler head 9 has been connected outside the plate capacitor 3 and the conductor head 10 has been connected outside the plate capacitor 5 according to figure 1. In the application according to figure 1 the plates of the plate capacitors as well as the conductor head and the coupler head are made of brass. The purpose of the plate capacitors is to create condensers in both ends. The size and the distance from the frame of the plate capacitors as well as the electrical material (the dielectric constant of the material) define the capacitance of the condensers formed by the plate capacitors. The capacitance of the capacitors as well as the other parts Of the coupler has influence on the frequency range passing the low pass filter of the coupler.

There is a conductor 4 going through the space 6 insulated by air in the frame and connected between the plate capacitors 3 and 5. The conductor in the space insulated by air represents the coil. The inductance of the coil depends on the material around the conductor as well as on the length and thickness of the conductor. Thus the parameters for the conductor are selected such that together with the plate capacitors it forms a low pass filter functioning on the frequency range of a desired communication network.

The plate capacitors 3 and 5 and the air insulated conductor 4 together form the low pass filter to coupler. The input and the output impedance of the low pass filter depend on the capacitance of the plate capacitors functioning as condensers and on the inductance of the conductor 4 functioning as a coil. The input and the output impedance are adjusted to the impedance of the system, which creates a good return attenuation on the desired frequency range. According to this principle the capacitance of the plate capacitors (condensers) of the filters according to figure 1 and the inductance of the conductor (coil) is selected such that the low pass filter they form allows the pass of the frequencies on the frequency range of the selected communication network but prevents the pass of other frequencies.

In figure 2 there is a pass attenuation curve (S21 -curve) 13 and return attenuation curve (S22-curve) 14 of the coupler pair formed of couplers according to figure 1. In the figure there is also demonstrated a frequency range of one recognized GSM- mobile network (lower limit 15 and upper limit 16) to which the coupler according to figure 1 has been applied. On the horizontal axis of the figure there is the frequency (MHz) and on the vertical axis the attenuation (dB). As can be seen in the figure 2 the return attenuation 14 of the low pass filter of the coupler strongly increases when approaching the frequency range of a mobile network. At this moment the pass attenuation is very low, so that the frequencies lower than the lower limit of the frequency range and the frequencies somewhat higher than those of the mobile network in question pass the filter with ease. Accordingly, after the upper limit of the frequency range the return attenuation begins to get smaller thus making the pass attenuation get higher, so the frequencies higher than the upper limit of the frequency range of the mobile network are not able to pass the filter.

The size, shape and materials in the frame of the coupler as well as components in it may vary. The frame may be manufactured according to some standard or in other way. Material may also be some other electrical conductive material than brass which has been used in the application according to figure 1. The coupler may also be coated, for example, with gold, silver or white bronze. The fixing part may be constructed of various fixing elements which may consist threads and flanges or fixing element of some other kind, with which the coupler can be fixed or to which other couplers or coupler heads can be fixed in a suitable way.

The quantity and the place of the capacitors in respect with the frame may vary. It is advantageous that the capacitors are plate capacitors, but they may include also parts that are equivalent with the capacitor plates but are of other shape than a plate, for instance, ball-shaped, diskshaped or of a shape of a curve ended I-letter viewed from the head. The thickness/diameter relationship of the plate-shaped capacitor plates may vary and they may differ from the round shape demonstrated in the application according to figure 1, like ellipse-shaped or of angular form. Capacitors. may be placed in both ends of the conductor or only in one end. There may also be several capacitors in one end of a conductor and the size of the capacitor plates or equivalent parts of equivalent condenser plate may vary. The electrical insulating material between the plate capacitors and the frame may be of any suitable electrical insulating material. As a matter of fact it may be chosen suitable in respect with the wanted capacitor to the capacitor and the size of the frame of the coupler or both of these.

The conductor insulated from the frame and being a part of the coupler may be manufactured of various conductor materials. Thickness, length and shape of the conductor may also vary. The shape of the conductor may be curved or rolled on a coil. Insulating material between the conductor and the frame may be of any suitable electrical insulating material. When gaseous material in question it may also be some other suitable gas than air. The pressure of gas may also differ from the air pressure in the application according to figure 1 and the temperature of gas may be controlled, in case the use of gas in question so requires.

The heads of the coupler may differ from the application according to figure 1. There may be more than one coupler head and the length, diameter and the pitch may vary in regard with the standard for the coupler and the impedance of the system. In stead of the coupler heads there may be conductor heads or there may be several conductor heads and coupler heads.

Functional properties of the components of the coupler according to the invention, like the capacitance of the condensers formed of plate capacitors and the inductance of the conductor, may vary in desired way. Thus the frequency range passing the filter in the coupler according to the invention may vary on a very large range, thus allowing to apply the coupler in communication networks on various frequency ranges.

The invention is not limited to the advantageous arrangements shown, but can vary within the idea of the invention within the limits set fort the claims.

Claims

1. A coupler, which consists of a frame (1) with a fixing part (2, 11, 12), a low pass filter (3, 4, 5) and one or several coupler heads (9), c h ar a c ter i s e d in that in the low pass filter there is at least one conductor (4) insulated from the frame and functioning as a coil and that there is one or several capacitors (3, 5) at least in one end of the conductor.

2. A coupler according to claim 1, c h ar a c t e r i s e d in that there is gaseous insulating material (6), like air between the conductor (4) and the frame.

3. A coupler according to claim 1 and 2, ch ar a c t e r i s e d in that there is electrical insulating material (7) between the capacitors (3, 5) and the frame (1).

4. A coupler according to one of claims 1-3, c h ara c t e ri s e d in that there are locking elements (8) between the frame (1) and electrical insulating material (7) in order to lock the electrical insulating material and the capacitor (5) to the place.

5. A coupler according to one of claims 1-4, c h ar a c t e ri s e d in that there is a conductor head (10) in one end of the coupler in order to connect the conductor to the coupler.

6. A coupler according to one of claims 1-5, c h ar a c t e ri s e d in that there is a coupler head (9) in one end of the coupler in order to connect the coupler to another coupler or to a conductor.

7. A coupler according to one of claims 1-6, c h ar a c t eri s e d in that the best return attenuation of the pass band of the low pass filter (3, 4, 5) has been adjusted to cover a frequency range of one or several communication networks, like mobile networks.

8. A coupler according to one of claims 1-7, c h ar a c t eri s e d in that the pass attenuation of the low pass filter (3, 4, 5) has been adjusted to prevent the pass of frequencies higher than those of communication networks.