A) TECHNICAL FIELD
[0001] The present invention generally relates to communication system and particularly to antenna in communication system. The present invention more particularly relates to an antenna in a wireless communication system for automated meter reading applications in energy meters.
B) BACKGROUND OF THE INVENTION
[0002] A remote meter reading system has been a reality for many years. The ultimate desire of meter manufacturers and large utility operators is to obtain meter readings automatically and directly from a central reading station. During last three decades, water utilities have seen meter reading evolve from manual entry readings to highly sophisticated, automatic meter reading systems. The automatic meter reading systems are fully automatic with little or no human intervention, and the data can be transmitted directly to a central location at the utility. The communication link can be a telephone network, cable TV system, electrical power main, or radio frequency (RF) based system.
[0003] With the advent of Automatic Meter Reading systems, the single phase and three phase meters are equipped with RF modems as well as RF hand held units for remote monitoring and control of the meters. There is a growing demand for wireless communication services. With this demand there is a need for low-cost miniaturized antennas. Additionally, it is desirable that the size of the communication apparatus and the transmitting or receiving antennas be small.

[0004] Basically for wireless communication, printed circuit board antennas like folded dipole, Inverted F antenna, and center fed dipole antenna are used and these antennas are having a dielectric loss and in most of the cases low cost substrate (Flame Retardant 4) FR4 is used. The FR4 substrate has a tangent loss of 0.02 which directly affects the gain of the antenna and which in turn will directly affect the range of communication between the transmitter and receiver. Moreover the space occupied by the antenna is more and which implicates on the cost of the printed circuit board (PCB) also. In the printed circuit board antenna, there is an insertion loss due to the substrate material which eventually affects on the range of the device. Hence there is a need to overcome the above drawback without affecting the cost of the device.
[0005] For application like Automatic Meter Reading (AMR), cost versus performance is a trade off and without increasing the cost, the performance of the low power radio frequency modem in terms of range is to be increased. Hence there is a need to improve the performance and to reduce the cost of using antennas in automated meter reading systems.
[0006] Thus there is a need for a low cost, robust, easily installable and simple antenna with improved sensitivity and range for Automatic Meter Reading applications.
[0007] The above mentioned shortcomings, disadvantages and problems are addressed herein and which will be understood by reading and studying the following specification.
C) OBJECTS OF THE INVENTION
[0008] The primary object of the present invention is to provide a miniature, Omni directional, inverted U-shaped wire anterma for automatic meter reading systems.

[0009] Yet another object of the present invention is to provide a miniature Omni directional wire antenna which uses air as substrate and which is mounted in the cutout area provided in the printed circuit board at the radio frequency (RF) modem module.
[0010] Yet another object of the present invention is to provide a miniature Omni directional wire antenna that is smaller in size and which is interfaced with the tri-vector meter as a retro-fit block for wireless data collection and communication.
[0011] Yet another object of the present invention is to provide a miniature Omni
directional wire antenna to increase the performance of the automatic meter reading
system.
[0012] Yet another object of the present invention is to provide a miniature Omni
directional wire antenna that occupies less space and which is easily replaced with the
another antenna when detuned to some other frequencies.
[0013] Yet another object of the present invention is to provide a miniature Omni directional wire antenna to eliminate the dielectric losses by using air as a substrate.
[0014] These and other objects and advantages of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings.
D) SUMMARY OF THE INVENTION
[0015] The various embodiments of the present invention provide an Omni directional wire antenna for automatic meter reading systems. According to one embodiment of the present invention, an Omni directional wire antenna system for energy meter has a RF modem module. A cutout provided in the printed circuit board

and a wire antenna mounted in the cutout. The cutout is formed by removing a portion at one edge of the printed circuit board. The wire antenna is an inverted U shaped antenna. The wire antenna is fine tuned to change the communication frequency. The one end of the inverted U shaped antenna will be connected to conductor line and other end is attached to PCB for mechanical stability. The wire antenna is mounted in the cutout at the printed circuit board to float in air.
[0016] According to one embodiment of the present invention, the inverted U-shaped wire antenna is mounted in the cutout provided on the radio frequency printed circuit board (PCB) module. The Omni directional wire antenna is provided to transmit tri-vector meter readings wirelessly to a data concentrator. It has more gain due to the absence of the dielectric loss by using air as a substrate and hence the enhanced performance.
[0017] According to one embodiment of the present invention, printed circuit board in a radio frequency modem is provided with a cutout for mounting a wire antenna. The wire antenna is constructed utilizing a copper wire of diameter 1.7mm and uses an air as a substrate. The inverted U-shaped antenna occupies an area of 1 cm2 and is mounted on the cutout provided in the radio frequency modem PCB module. Since wire antenna is floating in air, a provision is given in the PCB so that the other end of the wire antenna is soldered back in the PCB itself to give a mechanical support. Since the antenna has Omni directional characteristic and also the meter supports mesh networking, it is possible to measure the meter reading of one entire town or area with the help of a single meter reading instrument.
[0018] According to one embodiment of the present invention, the radio frequency modem printed circuit board module is interfaced with the tri-vector meter as a retro-fit block. With the help of this module, the tri-vector meter transmits the meter readings

wirelessly to data concentrator. The module communicates with the data concentrator in 2.4GHz ISM band. The radio frequency module printed circuit board module includes a controller to control the module and also to generate the RF signals. The module communicates with the tri-vector meter through UART communication and a power amplifier is used and finally matched to wire antenna to obtain the specific range of wireless operation. Even when there is any frequency shift due to enclosure/housing of the meter, the redesigning of the antenna is not required but only the tuning of the antenna is required. The system test is done on the module and no redesign is required.
[0019] The radio frequency modem printed circuit board module is provided to collect the data from three phase energy meters using wireless network protocol. The coordinator will collect the data from the end devices through the router devices or directly. It is a single master and multiple slave protocol, where request for data can be initiated only by the coordinator and the collected data will be stored by a personal computer end firmware. At any given time, only a single end-device can be polled for data by the coordinator, either directly or through hopping. The protocol to be designed is completely proprietary with minimum overheads on the meter firmware. The end devices will send response only when coordinator requests for data.
[0020] Hence the present invention provides an inverted U-shaped Omni directional wire antenna using which the dielectric loss is bypassed by using air as a substrate and a simple copper wire with diameter of 1.7 mm is used. The proposed antenna is having better gain than the conventional PCB antennas and is smaller in size. For application like Automatic Meter Reading (AMR), cost versus performance is a trade off and without increasing the cost, the performance of the low power RF modem in term of range is increased by 35 % in comparison with printed circuit anterma.
[0021] The Inverted U shaped wire antenna is provided to have a bandwidth of 300 MHz for a return loss less than 10dB. The major advantage of the present invention is

that, when the antenna is mounted inside the enclosure the frequency shifting due to enclosure effect still remains within the preset band and the manufacturing tolerance. Even for slight variation between the antennas, the radiation characteristics remain the same.
E) BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The other objects, features and advantages will occur to those skilled in the art from the following description of the preferred embodiment and the accompanying drawings in which:
[0023] FIG. 1 shows a front side plan view of the printed circuit board with a wire antenna for automatic meter reading system, according to one embodiment of the present invention.
[0024] FIG. 2 shows a block diagram of an automatic meter reading system for energy meter provided with a radio frequency modem mounted with a wire antenna, according to one embodiment of the present invention.
[0025] Although the specific features of the present invention are shown in some drawings and not in others. This is done for convenience only as each feature may be combined with any or all of the other features in accordance with the present invention.
F) DETAILED DESCRIPTION OF THE INVENTION
[0026] In the following detailed description, a reference is made to the accompanying drawings that form a part hereof, and in which the specific embodiments that may be practiced is shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments and it is to be

understood that the logical, mechanical and other changes may be made without departing from the scope of the embodiments. The following detailed description is therefore not to be taken in a limiting sense.
[0027] The various embodiments of the present invention provide an Omni directional wire antenna for automatic meter reading systems. According to one embodiment of the present invention, an Omni directional wire antenna system for energy meter has a printed circuit board for a communication modem. A cutout is provided in the printed circuit board and a wire antenna mounted in the cutout. The cutout is formed by removing a portion at one edge of the printed circuit board. The wire antenna is an inverted U shaped antenna wire antenna. The wire antenna is fine tuned to change the communication frequency. The ends of the wire antenna are soldered to the printed circuit board. The wire antenna is mounted in the cutout at the printed circuit board to float in air.
[0028] According to one embodiment of the present invention, the inverted U-shaped wire antenna is mounted in the cutout provided on the radio frequency printed circuit board (PCB) module. The Omni directional wire antenna is provided to transmit tri-vector meter readings wirelessly to a data concentrator.
[0029] According to one embodiment of the present invention, a radio frequency modem printed circuit board module is provided with a cutout for mounting a wire antenna. The wire antenna is constructed utilizing a copper wire of diameter 1.7mm and uses an air as a substrate. The inverted U-shaped wire antenna occupies an area of 1 cm and is mounted on the cutout provided in the radio frequency modem PCB module. Since the wire antenna is floating in air, a provision is given in the PCB so that the other end of the wire antenna is soldered back in the PCB itself to give mechanical stability. Since the antenna has Omni directional characteristic and also the meter supports mesh

networking, it is possible to measure the meter reading of one entire town or area with the help of single meter reading instrument.
[0030] According to one embodiment of the present invention, the radio frequency modem printed circuit board module is interfaced with the tri-vector meter as a retro-fit block. With the help of this module, the tri-vector meter transmits the meter readings wirelessly to data concentrator. The module communicates with the data concentrator in 2.4GHz ISM band. The radio frequency module printed circuit board module includes controller to control the module and also to generate the RF signals. The module communicates with the tri-vector meter through UART communication. To obtain the specific range of wireless operation, a power amplifier is used and is finally matched to wire antenna. Even when there is any frequency shift due to enclosure/housing of the meter, the redesigning of an anterma is not required but only the antenna is to be tuned. The RF modem is integrated with meter and system test is done and no redesign is required.
[0031] The radio frequency modem printed circuit board module is provided to collect the data from three phase energy meters using wireless network protocol. The coordinator will collect data from end devices through router devices or directly. It is a single master and multiple slave protocol, where request for data can be initiated only by the coordinator and the collected data will be stored by a personal computer end firmware. At any given time, only a single end-device can be polled for data by the coordinator, either directly or through hopping. The protocol to be designed is completely proprietary with minimum overheads on the meter firmware. End devices send response only when a coordinator asks for a data.
[0032] Hence the present invention provides an inverted U-shaped Omni directional wire antenna using which the dielectric loss is bypassed by using air as a substrate and a simple copper wire with diameter of 1.7 mm is used. The proposed antenna is

having better gain than PCB antennas and smaller in size. For application like Automatic Meter Reading (AMR), cost versus performance is a trade off and without increasing the cost the performance of the low power modem in term of range is increased by 35 % in comparison with printed circuit antenna.
[0033] The Inverted U-shaped wire antenna is provided to have a bandwidth of 300 MHz for a return loss less than lOdB. The major advantage of the present invention is that, when the antenna is mounted inside the enclosure, the frequency shifting due to enclosure effect still remains within transmission band and the manufacturing tolerance. Even for the slight variation between antennas, the radiation characteristics remain the same.
[0034] FIG. 1 shows a front side plan view of the printed circuit board with a wire antenna for automatic meter reading system, according to one embodiment of the present invention. With respect to FIG.l, a printed circuit board 1 provided in a wireless communication module such as a radio frequency modem has a cutout area 2 for mounting an Omni directional wire antenna 3. The wire antenna 3 is constructed using a copper wire of diameter 1.7mm and uses air as a substrate. The wire antenna 3 occupies an area of 1 cm2 and is mounted in the cutout 2 provided on the printed circuit board (PCB). One end 4 of the Omni directional wire antenna 3 is soldered in the cutout 2 provided in PCB and the other end 5 of the wire antenna 3 is soldered back in the PCB cutout 2 to provide mechanical stability.
[0035] FIG. 2 shows a block diagram of an automatic meter reading system for energy meter provided with a radio frequency (RF) modem mounted with a wire antenna, according to one embodiment of the present invention. With respect to FIG. 2, a printed circuit board 1 provided in the radio frequency modem has a cutout for mounting a wire antenna. The modem is interfaced with the tri-vector meter 6. The RF modem module communicates with the Tri-vector meter 6 through UART

communication and to collect data from the tri-vector meter. The radio frequency modem transmits the meter readings wirelessly to a data concentrator.
[0036] The RF Modem is provided to collect data from three phase energy meter using wireless network protocol. The coordinator will collect data from the end devices through the router devices or directly. It is a single master and multiple slave protocol, where request for data is initiated only by the coordinator and the collected data is stored by a personal computer end firmware. At any given time, only a single end-device is polled for data by the coordinator, either directly or through hopping. The protocol to be designed is completely proprietary with minimum overheads on the meter firmware. End devices send response only when a coordinator requests for a data. The wire antenna 3 is mounted as a retro-fit block. This is a retro-fit on feature of wireless data collection to the already existing product of tri vector meter 6. The new parts added on the already existing meter include the controller to control the module and also to generate the RF signals.
G) ADVANTAGES OF THE INVENTION
[0037] The various embodiments of the present invention provide a miniature, inverted U-shaped Omni directional wire antenna for automatic meter reading systems. The wire antenna is constructed utilizing a copper wire and uses air as a substrate. The dielectric loss in the printed circuit board antenna is bypassed by using air as a substrate. The inverted U-shaped Omni directional wire antenna is smaller in size and has better gain than conventional PCB antennas. The design of wire antenna is very simple hence without increasing the cost of design, the performance of the low power modem in terms of range is increased by 35 % in comparison with the conventional printed circuit antenna. The Inverted U shaped wire antenna is provided to have a bandwidth of 300 MHz for a return loss less than lOdB. The major advantage of the present invention is that, when the antenna is mounted inside the enclosure the frequency shifting due to

enclosure effect still remains in band and even if there is slight variation between antennas the radiation characteristics remains same. Since the antenna has Omni directional characteristic and also the meter supports mesh networking it is possible to measure the meter reading of one town or area with the help of one meter reading instrument.
[0038] Although the invention is described with various specific embodiments, it will be obvious for a person skilled in the art to practice the invention with modifications. However, all such modifications are deemed to be within the scope of the claims.
[0039] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the present invention described herein and all the statements of the scope of the invention which as a matter of language might be said to fall there between.

CLAIMS
What is claimed is:
1. An Omni directional wire antenna system for energy meter comprising:
A printed circuit board for a communication modem;
A cutout provided in the printed circuit board; and A wire antenna mounted in the cutout.
2. The system according to claim 1, wherein the cutout is formed by removing a
portion at one edge of the printed circuit board.
3. The system according to claim 1, wherein the wire antenna is an inverted U
shaped wire antenna.
4. The system according to claim 1, wherein the wire antenna is fine tuned to
change the communication frequency.
5. The system according to claim 1, wherein the ends of the wire antenna are
soldered to the printed circuit board.
6. The system according to claim 1, wherein the wire antenna is mounted in the
cutout at the printed circuit board to float in air.

To,
The Controller of Patents,
The Patent office, At Chennai