Broadband tree switch architecture for reducing pulse width narrowing

Abstract

A broadband space tree-switch matrix establishes a desired switching path by sensitizing only the sequence of logic gates defined by the desired path such that only these sensitized logic gates are operable to undergo switching and thereby permit transmission of only the corresponding input signal. The tree-switch includes a plurality of cascaded stages wherein the first stage consists of dual-input NAND gates each receiving a corresponding input signal at one input and a control signal at another input. The remaining stages include a plurality of switching nodes each having a first NAND gate cascaded to a second NAND gate wherein the second NAND gate has a HIGH steady-state logic signal present at one of its inputs. An appropriate combination of control signals are applied to the NAND gates in the first stage to effect a selected switching path. A second broadband space switch matrix comprises a plurality of NAND gates arranged into a series of cascaded stages to form a tree-switch configuration. The first and second stages include equal numbers of NAND gates corresponding to the number of input signals. Furthermore, the NAND gates in only the first and second stages each have a control input for receiving control signals to establish a selected path. The tree-switch likewise operates to sensitize a particular path in response to the control signals so that only the NAND gates in the selected path are operable to undergo switching.