Multi-stage modulator system

Claim 2

A multi-stage modulator system for forming, starting from voice frequency channels, a standard frequency multiplex group, comprising a first modulator group including a plurality of premodulated voice frequency channels each having a first modulator receiving respective input signals and respective modulation signals and a first filter connected directly to the outputs of said first modulators in common, a second modulator group including a plurality of second modulators each receiving the output of said first filter and a respective modulation signal and a second filter connected directly to the outputs of said second modulators in common, and a third modulator group including a plurality of third modulators each receiving the output of said second filter and a respective modulator signal and a third filter connected directly to the outputs of said third modulators in common, each of the modulators of each modulator group supplying a single modulation sideband within a given frequency band.

Claim 3

A multi-stage modulator system as defined in claim 1 wherein said first modulator group further includes a respective premodulator connected in each channel to receive a respective one of said input signals and a common modulation signal, the outputs of said premodulators being connected to the inputs of respective first modulators in the respective channels.

Claim 4

A multi-stage modulator system as defined in claim 2 wherein said second modulator group further includes a plurality of fourth filters connecting the output of said first filter to each of said second modulators.

Claim 5

A multi-stage modulator system as defined in claim 3 wherein said third modulation group further includes a plurality of fifth filters connecting the output of said second filter to each of said third modulators.

Claim 6

A multi-stage modulator system as defined in claim 4 wherein said first modulation group further includes a plurality of sixth filters interconnecting said premodulators to said first modulators.

Claim 7

A multi-stage modulator system for converting voice frequency channels into a standard frequency multiplex group comprising n modulator stages, where n is an integer equal to or greater than 2, each modulator stage lower than the nth stage including a plurality of modulator groups, the nth stage having a single modulator group supplying said standard frequency multiplex group, each modulator group comprising a plurality of modulators having one input connected to receive a respective modulation signal and a second input conNected to receive a respective input signal, the second inputs of the modulators in the first multiplex stage being connected to means providing respective premodulated voice frequency channels, the second inputs of the modulators in the multiplex stages subsequent to the first multiplex stage being connected to the respective outputs of modulator groups of one unit lower rank in the preceding modulator stage, each of the modulators of each individual group supplying a single modulation sideband within a given frequency band at the output of the modulator group and having their outputs directly coupled in common connection to a single group band-pass filter.

Claim 8

A multi-stage modulator system for converting voice frequency channels into a standard frequency multiplex group comprising n modulator stages, where n is an integer equal to or greater than 2, each modulator stage lower than the nth stage including a plurality of modulator groups, the nth stage having a single modulator group supplying said standard frequency multiplex group, each modulator group comprising a plurality of modulators having one input connected to receive a respective modulation signal and a second input conNected to receive a respective input signal, the second inputs of the modulators in the first multiplex stage being connected to means providing respective premodulated voice frequency channels, the second inputs of the modulators in the multiplex stages subsequent to the first multiplex stage being connected to the respective outputs of modulator groups of one unit lower rank in the preceding modulator stage, each of the modulators of each individual group supplying a single modulation sideband within a given frequency band at the output of the modulator group and having their outputs directly coupled in common connection to a single group band-pass filter.