Distributed amplifier

Percival's design did not gain widespread awareness however, until a publication on the subject was authored by Ginzton, Hewlett, Jasberg, and Noe in 1948.

The latter contributes much to the availability of higher quality-factor (Q-factor or simply Q) integrated passive devices in the III-V semiconductor technologies.

To meet the marketplace demands on cost, size, and power consumption of monolithic microwave integrated circuits (MMICs), research continues in the development of mainstream digital bulk-CMOS processes for such purposes.

[8] The operation of the DA can perhaps be most easily understood when explained in terms of the traveling-wave tube amplifier (TWTA).

The DA consists of a pair of transmission lines with characteristic impedances of Z0 independently connecting the inputs and outputs of several active devices.

Unlike the multiplicative nature of a cascade of conventional amplifiers, the DA demonstrates an additive quality.

For example, for voltage inverting and current amplifying the input and the output form a shielded balanced line.

These delay lines do not have a flat dispersion near their cut off, so it is important to use the same L-C periodicity in the input and the output.

For narrow band operation other methods of phase-matching are possible, which avoid feeding the signal through multiple coils and capacitors.

Voltage can be amplified by a common gate transistor, which shows no miller effect and no unit gain frequency cut off.

The common gate configuration is incompatible with CMOS; it adds a resistor, that means loss, and is more suited for broadband than for high efficiency applications.