418 to bond pad 430 for example the air bridges 425 1 to 425 n may be substantially parallel to one another and the coupled line 427 may run substantially perpendicular to the air bridges 425 1 to 425 n the coupled line 427 is shown as having two ports a first port being connected to output detector 460 and a second port being connected to ground through resistor 421 the output detector 460 may determine a power level of the output of the power amplifier 410 which may be used for system power level setting or amplifier linearization for example it is understood that the first port and or the second port of the coupled line 427 may be connected to various other devices such as auxiliary amplifiers or other circuits used for linearization of the amplifier 410 and or passive networks such as resistance capacitor and or inductor circuits without departing from the scope of the present teachings for example the second port of the coupled line 427 may be connected to an auxiliary amplifier while the first port is connected to the output detector 460 also the coupled line 427 may be connected to an input of another amplifier for driving the other amplifier alternative configurations are discussed below with reference to fig4 b to 4e it is further understood that in various configurations the air bridge coupler 420 may be connected to the output of one or more previous stages e g the drain 414 of the first transistor 411 of the amplifier 410 instead of or in addition to being connected to the output of.