MEANDER LINE ANTENNA COUPLER AND SHIELDED MEANDER LINE

摘要

A switched meander line structure is substituted for a lumped element coupler (10) for an order of magnitude increase in gain due to the use of the switched meander line architecture. The use of the meander line (20) with relatively wide and thick folded legs markedly decreases I2R losses over wire inductors whose wire diameters at one-tenth of an inch contribute significantly to I2R losses. Additionally, placing solid state switches to short out various sections of a multi-leg meander line at high impedance nodes reduces I2R losses across the switching elements in the coupler. It has been found that, regardless of the impedance of the antenna, this impedance may be matched by switching in and out various sections of a folded multileg meander line due to the fact that the square of the sum of the capacitive reactances of the meander line decreases with frequency in synchronism with the unloaded Q of the meander line, thus to provide the ability to maintain a good match over frequency as the meander line is tuned to achieve resonance by shorting out combinations of sections of the meander line. The result of the substitution of the meander line architecture for the lumped element coupler is the reduction of losses associated with the use of wire inductors and losses due to the interposition of solid state switches at high-current nodes.