RF power measurements are essential in any RF product phase: design, production, maintenance, alignment and service. Hence, it is very important to have a RF power meter which can provide high speed measurements in a production environment, as well as the simplicity of operation for bench top or field use. Boonton 4240 series average power meters are the successors of 4230 series. This average power meter series is fully backwards compatible and can be paired with all available Boonton CW diode and Thermocouple sensors. The power meters automatically load frequency-response data stored in the memory of the sensors when they are connected. In addition, older sensors can be upgraded with a data adaptor in order to take advantage of this automatic calibration feature in the meters.
Fig 1: Boonton 4240 performs better than any legacy average power meter
4240 allows to measure RF power from -70 dBm to +44 dBm with a maximum dynamic range of 90 dB which is very similar to Boonton’s legacy product 4300 series, but it has higher measurements speed (200 readings/sec for 1 CH) than 4300’s measurement rate (100 readings/sec). The frequency range is 10 kHz to 40 GHz for RF power measurements and 10 Hz to 1.2 GHz for voltage measurements (optional). This meter also includes standard GPIB and RS-232 interfaces for connection to external computers and ATE systems for display and processing of measurement results. Integration of either power meter into an ATE system is routine by means of simple software control via SCPI language or a Lab VIEW driver from National Instruments.
Automatic step calibration “AutoCal” function uses built-in 50 MHz sweep calibrator to offer best-in-class power linearity.
The instrument can measure gain and output power, and perform sum, difference, ratio and relative measurements. Selectable dual bar graphs assist with gain and peaking adjustments.
Why 4240 is still the best choice?
There are several reasons why I believe that 4240 series is the best choice as an average power meter. It helps to reduce test and alignment time due to its very fast measurement process capability with the convenient display either in logarithmic or linear units with five digit resolution. 4240 has channel math functionalities for up to two channels which is not that great compared to 4300’s six channel math functions. But It has another great feature of selectable dual bar graphs assistance with gain and peaking adjustments and also has a low power consumption. 4240 also has the capabilities of HP437/438 emulation and also legacy Boonton 4220A/4230A emulation. Moreover, it has a very reliable Boonton quality at a very affordable price.
 Data Sheet for Boonton 4240 Series RF Power Meter (ttp://boonton.com/~/media/Boonton/Datasheets/4240_Series_Datasheet_WEB.ashx )
 Boonton 4240 Product Information (http://boonton.com/products/power-meters/4240-rf-power-meter )