Trans-grade communication network

A method of incorporating an RF antenna into a grade-level opening cover, comprising:

• creating a slot in the grade-level opening cover to radiate at a predetermined radio frequency;
• connecting one line of a transmission line to a first side of said slot;
• and
• connecting another line of said transmission line to a second side of said slot.

A grade-level cover RF transceiver, comprising:

• a grade-level cover having a first slot therethrough, said slot sized and shaped to radiate at a predetermined radio frequency;
• a first cable having first and second conductors connected to first and second sides of said slot, respectively;
• and
• an RF transceiver connected to said first cable.

A grade-level cover RF transceiver, comprising:

• a grade-level cover having a first slot therethrough, said slot sized and shaped to radiate at a predetermined radio frequency;
• a first cable having first and second conductors connected to first and second sides of said slot, respectively;
• an RF transceiver connected to said first cable;
• a second slot through said grade-level cover said second slot having the same size and shape as said first slot;
• a second cable having first and second conductors connected to first and second sides of said second slot, respectively;
• and
• an RF switch connected to said first and second cables and controlled by said RF transceiver for switching between said slots.

A trans-grade communication network, comprising:

• a below-grade communication device;
• an above-grade communication device;
• and
• a grade-level cover incorporating first and second antennas and associated feeds for RF communications between said below-grade communication device and said above-grade communications device, said first and second antennas having slots of the same size and shape;
• and
• an RF transceiver connected to said first and second antennas and configured for antenna selection.

A method of incorporating an RF antenna into a grade-level opening cover, comprising:

• creating a slot in the grade-level opening cover to radiate at a predetermined radio frequency;
• connecting one line of a transmission line to a first side of said slot;
• and
• connecting another line of said transmission line to a second side of said slot;
• wherein said slot has sidewalls and end walls defining a vertical space extending through and below said cover, said method further comprising:
• mounting a coaxial connector on the underside of said cover with an inner conductor and outer conductor of said coaxial connector positioned within said vertical space;
• mechanically supporting said coaxial connector within said vertical space with a metallic coupler mechanically and electrically connected to said outer conductor and to the first side of said slot;
• and
• electrically connecting said inner conductor to the second side of said slot.

A grade-level cover RF transceiver, comprising:

• a grade-level cover having a first rectangular slot therethrough, said slot sized and shaped to radiate at a predetermined radio frequency;
• a first cable having first and second conductors connected to first and second sides of said slot, respectively;
• an RF transceiver connected to said first cable;
• a second rectangular slot through said grade-level cover, substantially orthogonal to said first slot, and sized and shaped to radiate at a predetermined radio frequency;
• a second cable having first and second conductors connected to first and second sides of said second slot, respectively;
• and
• an RF switch connected to said first and second cables and controlled by said RF transceiver for switching between said slots, said RF switch including an impedance matching network having a two-stage impedance tuner.