Active phased array adjustment using transmit amplitude adjustment range measurements

An RF drive leveling adjustment method of use with an active phased array antenna system having a transmit module comprising a transit RF drive amplifier, said method comprising the steps of:

• calibrating the transmit RF drive amplifier for a predetermined transmit duty factor and pulse repetition frequency;
• making relative RF measurements of transmit amplitude adjustment range of the transmit module for a number of duty factors and pulse repetition frequencies spanning operating conditions to be encountered by the system;
• determining correction factors for RF drive levels of the transmit RF drive amplifier such that a constant amplitude adjustment range of the transmit module is maintained;
• and
• adjusting the RF drive level of the transmit RF drive amplifier using the correction factors,
• wherein the active phased array antenna system comprises transmit/receive modules that share an attenuator for both transmission and reception and wherein the step of determining the correction factors for the transmit/receive modules comprises computing the correction factors using the equation:
• G.sub.max,R /G.sub.min,R =A.sub.R, and G.sub.max,T /G.sub.min,T =A.sub.T =A.sub.R /A.sub.comp, (G.sub.max,R /G.sub.min,R)/(G.sub.max,T /G.sub.min,T)=A.sub.R /A.sub.R /A.sub.comp =A.sub.comp =transmit gain compression, A.sub.comp =a constant for fixed operating conditions,
• where:
• G.sub.max,T is the maximum elemental gain when transmitting, G.sub.min,T is the minimum elemental gain when transmitting, A.sub.T is the transmit amplitude adjustment range. G.sub.max,R is the maximum elemental gain when receiving, G.sub.min,R is the minimum elemental gain when receiving, A.sub.R is the receive amplitude adjustment range.