Electrical filter arrangement

Claim 2

A multistage electrical filter network for selectively notching at least one selected frequency from a frequency band comprising: a. means for receiving said frequency band from a source thereof; b. a plurality of attenuating means in electrical series with the path of travel of said frequency band and presenting a high impedance to the selected frequency while presenting a low impedance to the nonselected frequencies in said frequency band, each of said series attenuating means including a parallel LC network resonant at the selected frequency, said inductance values chosen to have optimum Q at the selected frequency; c. a plurality of attenuating means in electrical shunt with the path of travel of said frequency band, and presenting a low impedance to the selected frequency while presenting a high impedance to the nonselected frequencies in said frequency band, said series and said shunt attenuating means being alternately disposed in circuit relationship with one another, each of said shunt attenuating means comprising a series LC circuit resonant at the selected frequency, said inductance values chosen to have optimum Q at the selected frequency; d. transformer means electrically coupling adjacent attentuating means to each other and matching the impedances of said adjacent attenuating means to each other; and e. means for receiving the frequency band from the last of said attenuating means and for delivering the frequency band to an output circuit.

Claim 3

An electrical filter network as described in claim 1 wherein each of said series attenuating means comprises a transformer having a primary and a secondary winding, said primary winding being in electrical series with the path of travel of the said frequency band and said secondary winding having capacitance means in electrical shunt thereacross, said secondary winding and said capacitance means forming a parallel LC circuit resonant at the sElected frequency, said secondary winding being of an inductance value to have optimum Q at the selected frequency.

Claim 4

An electrical filter network as described in claim 2 wherein each secondary winding and shunt-stage inductance is substantially identical as to inductance value and Q.

Claim 5

A multistage passive electrical filter network for selectively notching a predetermined frequency from a band of energy comprising: a. a first passive attentuating means in electrical series to the path of travel of the band of energy and presenting a high impedance to the selected frequency while presenting a low impedance to the nonselected frequencies in the band; b. a first passive attenuating means in electrical shunt to the path of travel of the band of energy and presenting a low impedance to the selected frequency while presenting a high impedance to the nonselected frequencies in the band; c. transformer means coupling said first series attenuating means to said first shunt attenuating means and matching the impedance of said first series attenuating means to said first shunt attenuating means; d. a second passive attenuating means in electrical series to the path of travel of the band of energy and presenting a high impedance to the selected frequency while presenting a low impedance to the nonselected frequencies in the band; e. transformer means coupling said second series attenuating means to said first shunt attenuating means and matching impedance of said second series attenuating means to said first shunt attenuating means; f. a second passive attenuating means in electrical shunt to the path of travel of the band of energy and presenting a low impedance to the selected frequency while presenting a high impedance to the nonselected frequencies in the band; g. transformer means coupling said second shunt attenuating means to said second series attenuating means and matching the impedance of said second shunt attenuating means to said second series attenuating means; h. third passive attenuating means in electrical series to the path of travel of the band of energy and presenting a high impedance to the selected frequency while presenting a low impedance to the nonselected frequencies in the band; i. transformer means coupling said third series attenuating means to said shunt attenuating means and matching the impedance of said third series attenuating means to said second shunt attenuating means; j. third passive attenuating means in electrical shunt to the path of travel of the band of energy and presenting a low impedance to the selected frequency while presenting a high impedance to the nonselected frequencies in the band; k. transformer means coupling said third shunt attenuating means to said third series attenuating means and matching the impedance of said third shunt attenuating means to said third series attenuating means; l. each of said series attenuating means including a parallel LC circuit resonant at the selected frequency, each of said inductances being selected to be of optimum Q at the ''''notch'''' frequency; and m. each of said shunt attenuating means including a series LC circuit resonant at the ''''notch'''' frequency, each of said inductances being selected to be of optimum Q at the ''''notch'''' frequency.

Claim 6

A multistage passive electrical filter network for selectively notching a predetermined frequency from a band of energy comprising: a. a first passive attentuating means in electrical series to the path of travel of the band of energy and presenting a high impedance to the selected frequency while presenting a low impedance to the nonselected frequencies in the band; b. a first passive attenuating means in electrical shunt to the path of travel of the band of energy and presenting a low impedance to the selected frequency while presenting a high impedance to the nonselected frequencies in the band; c. transformer means coupling said first series attenuating means to said first shunt attenuating means and matching the impedance of said first series attenuating means to said first shunt attenuating means; d. a second passive attenuating means in electrical series to the path of travel of the band of energy and presenting a high impedance to the selected frequency while presenting a low impedance to the nonselected frequencies in the band; e. transformer means coupling said second series attenuating means to said first shunt attenuating means and matching impedance of said second series attenuating means to said first shunt attenuating means; f. a second passive attenuating means in electrical shunt to the path of travel of the band of energy and presenting a low impedance to the selected frequency while presenting a high impedance to the nonselected frequencies in the band; g. transformer means coupling said second shunt attenuating means to said second series attenuating means and matching the impedance of said second shunt attenuating means to said second series attenuating means; h. third passive attenuating means in electrical series to the path of travel of the band of energy and presenting a high impedance to the selected frequency while presenting a low impedance to the nonselected frequencies in the band; i. transformer means coupling said third series attenuating means to said shunt attenuating means and matching the impedance of said third series attenuating means to said second shunt attenuating means; j. third passive attenuating means in electrical shunt to the path of travel of the band of energy and presenting a low impedance to the selected frequency while presenting a high impedance to the nonselected frequencies in the band; k. transformer means coupling said third shunt attenuating means to said third series attenuating means and matching the impedance of said third shunt attenuating means to said third series attenuating means; l. each of said series attenuating means including a parallel LC circuit resonant at the selected frequency, each of said inductances being selected to be of optimum Q at the ''''notch'''' frequency; and m. each of said shunt attenuating means including a series LC circuit resonant at the ''''notch'''' frequency, each of said inductances being selected to be of optimum Q at the ''''notch'''' frequency.

Claim 7

A filter network as described in claim 4 wherein each of said series attenuating means comprises a transformer having a primary winding and a secondary winding, each said secondary winding having connected thereacross capacitance means, said secondary winding and said capacitance means forming a parallel LC circuit resonant at the selected frequency, said secondary winding having optimum Q at the ''''notch'''' frequency.

Claim 8

A filter network as described in claim 4 wherein the inductances in said parallel and series LC circuits are substantially identical as to value and Q, for any given ''''notch'''' frequency.

Claim 9

A filter network as described in claim 5 wherein each secondary winding is identical as to inductance value and Q.

Claim 10

A filter network for selectively ''''notching'''' a predetermined number of frequencies from a frequency band, the combination comprising: a. means for receiving said frequency band from a source thereof; b. a plurality of groups of series attenuating stages, each group containing a number of series connected filters equal to the number of predetermined frequencies; c. a plurality of groups of parallel attenuating stages, each group containing a number of parallel connected stages equal to the number of predetermined frequencies; d. transformer impedance matching means coupling adjacent groups of attenuating means to each other and matching the impedances of said adjacent groups to each other; e. means for receiving the ''''notched'''' frequency band from the last of said groups; and f. means for delivering the ''''notched'''' frequency band to an output circuit.

Claim 11

A filter network for selectively ''''notching'''' a predetermined number of frequencies from a frequency band, the combination comprising: a. means for receiving said frequency band from a source thereof; b. a plurality of groups of series attenuating stages, each group containing a number of series connected filters equal to the number of predetermined frequencies; c. a plurality of groups of parallel attenuating stages, each group containing a number of parallel connected stages equal to the number of predetermined frequencies; d. transformer impedance matching means coupling adjacent groups of attenuating means to each other and matching the impedances of said adjacent groups to each other; e. means for receiving the ''''notched'''' frequency band from the last of said groups; and f. means for delivering the ''''notched'''' frequency band to an output circuit.

Claim 12

A filter network as described in claim 8, wherein each series and parallel group has one filter which has an inductance and Q value which is substantially identical to one filter in each other group.

Claim 13

A filter network as described in claim 9, wherein each series connected filter comprises a transformer having a primary and a secondary winding, said primary winding being in electrical series with the path of travel of said frequency band and said secondary winding having capacitance means in electrical shunt thereacross, said secondary winding and said capacitance means forming a parallel LC circuit resonant at the selected frequency, said secondary winding being of an inductive value to have optimum Q at the selected frequency.

Claim 14

A filter network as described in claim 10, wherein said means for receiving comprises a source impedance matching transforming means whereby the source impedance is coupled to the series LC circuit through the source transforming means and the series connected filter transformer.