Electromagnetic coupler system

• US 6,963,305 B2
• Filed: 10/02/2002
• Issued: 11/08/2005
• Est. Priority Date: 10/02/2002
• Status: Active Grant

• Current Assignee: Guenther Knapp
• Original Assignee: Guenther Knapp
• Inventors: Knapp, Guenther
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US10/263,143
• Publication Number:
  US 20040066326A1
• Time in Patent Office: 1,133 Days
• Field of Search: 342/350, 342/367, 333/81.R, 333/81.A, 333/230, 455/41.1, 455/41.2
• US Class Current: 342/367
• CPC Class Codes: H01Q 1/1285 with capacitive feeding through the windscreen
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 92/02 Inter-networking arrangements
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

This invention makes it possible to communicate through solid non-metallic walls or ceilings with low microwave power levels. RF beam forming couplers are driven by common networks.

For connection to a LAN segment at the other side of a wall or ceiling, transceiver 4 transmits data modulated microwave RF to coupler 6 through a directional step attenuator 10. The reduced signal is received by the coupler system at the other side with a power level low enough to eliminate wireless detection from the outside. However, the directional step attenuator on the receive side reduces the signal power only by an insignificant amount due to its low directional losses during receive signal flow. Each coupler'"'"'s geometry is minimizing the radiation exposed material volume by RF field concentration, therefore, enabling transmission through thick concrete walls at microwave frequencies without compromising privacy. When used as wireless access point, coupler transmits through a floor to wireless devices below. The preferred embodiment operates in the 5-GHz ISM band.

Claims

1. An electromagnetic microwave coupler system for wired, fiber optic and wireless information networks to provide wireless communication through a wall or ceiling of various composition without its alteration, comprising:

a transceiver with data controller providing a bridging means for transmission and reception of information modulated microwave signals;

microwave coupling device of wavelength-related design for transmission and reception of said microwave signals through said wall or ceiling by using a radio frequency conductive and reflective housing structure with an aperture limited by a Brewster'"'"'s angle creating a confined electromagnetic radiation field through said wall or ceiling in interaction with an antenna means placed within said structure and located close to said wall or ceiling;

wherein, a RF conductive and reflective shielding means is part of said coupling device and is designed such that the said shielding means is surrounding the said aperture to prevent backward radiation of said radiation field while restricting the microwave signal penetration to as small as possible volume;

at least one means is provided to secure said microwave coupling device to said wall or ceiling;

a microwave signal attenuation means having bi-directional means with low forward signal power losses and high isolation attenuation is provided for control of transmitted said microwave signals to optimize power for a specific said wall or ceiling type and thickness;

said antenna means comprises at least one resonator used for both transmission and reception; and

,

at least one said microwave coupler system each with at least one said coupling device located above the ceiling or behind a wall of a building providing at least one wireless access point for communication through said wall or ceiling to communicate with wireless devices having their own antennas located below or behind said wall or ceiling; and

,

a second said microwave coupler system is placed at the opposite side of said wall or ceiling for communication with said first microwave coupling device for reception and transmission of said microwave signals through said wall or ceiling.

2. A microwave coupler system according to claim 1 wherein:

said antenna means is designed by approximation with a set of equations selected from prior art for various microwave antennas with their dielectric and metal structures to obtain the desired frequency, bandwidth and gain; and

,

said structure enclosing said antenna means with a one-sided opening for projecting microwave radiation outwards to penetrate said wall or ceiling with a minimum of reflected said microwave radiation from said wall or ceiling; and

,

a connecting means is with at least one impedance matching transmission path connected to said antenna means; and

,

said antenna means with said connecting means and said structure with and without said shielding means and said wall or ceiling are evaluated by electromagnetic simulation for correction of said approximation for optimizing the location of the said antenna means for proximity to said structure and said wall or ceiling for avoidance of capacitive effects and to optimize wave phases, whereby concentrating the said microwave radiation to a desired exit area with a desired propagation lobe within and external of said wall or ceiling to minimize microwave power losses for said microwave coupler system.

3. A microwave coupler system according to claim 2 wherein:

said RF conductive and reflective shielding means is combined with said structure having a minimum area of about one half-wavelength square whereby reducing RF power leakage by backward radiation and to increase the microwave coupling efficiency.

4. A microwave coupler system according to claim 3 wherein:

said means to secure said coupling device to said wall or ceiling is included by said shielding means in forming a mounting and standing support bracket whereby expediting installation of portable and temporary network setups.

5. A microwave coupler system according to claim 4 wherein said attenuation means, comprising:

at least one radio frequency isolator means with low forward power losses and high isolation attenuation using its predetermined isolation attenuation to reduce the power of said microwave signals in one direction of signal flow and using its lower forward attenuation for said microwave signals to flow in the opposite direction; and

;

at least one attenuation means is connected serially into the path of said microwave signals between said bridging means and said coupling device whereby optimizing the received said microwave signals and minimizing the transmitted signal power for reduction of microwave power leakage by manual connection of the amount of said attenuation means required.

6. A microwave coupler according to claim 5 wherein said attenuation means comprising:

a switching engaged plurality of said attenuation means;

at least one said attenuation means with impedance matched ports for forward and backward signal flow; and

,

a plurality of low cross talk switching means providing impedance matched engaging of at least one said attenuation means whereby resulting in the directional step attenuator.

7. A microwave coupler system according to claim 4 wherein:

said directional step attenuator is placed into said microwave signals path of said bridging means and said coupling device whereby optimizing the received signal power and minimizing the transmitted signal power for wide ranges of wall or ceiling thickness and material types by manual switching or by automatic control signals from said bridging means.

8. A microwave coupler system according to claim 7 with said coupling device placed at said wall or ceiling wherein:

second said second microwave coupler system according to claim 7 is located at the opposite of said wall or ceiling with its coupling device placed against the opposite side of said wall or ceiling segment at the opposite side of said wall or ceiling whereby the closest location to said coupling device on the opposite side is determined by the received said microwave signals power maximum obtained during setup by the transceiver within said bridging means or by a RF power metering device.