Low frequency active load pull tuner
View Patent ↗A low frequency active load pull tuner allows creating and controlling the reflection factor in a different frequency range than the operation frequency. It includes an active feedback loop and a remotely controlled digital electronic tuner, wherein the electronic tuner operates at an ordinary octave wide (Fmax/Fmin=2) frequency range (i.e. as an example 1-2 GHz), which leads to a low intermediate frequency band of 6 octaves or more. All required MHz range components for the tuner, except the custom-made digital electronic tuner, are readily available.
1. A low frequency active load pull tuner having a test port, comprising
a) a coupling module having input, output and coupled port,
b) an up- and a down-conversion module, each having LO, RF and IF ports,
c) a local oscillator,
d) a digital electronic tuning module having input and output port,
e) a low pass filter having input and output port, and
f) an amplifier having input and output port;
wherein
the test port of the active load pull tuner is connected to an output port of a DUT,
the input port of the coupling module is connected to the test port of the tuner,
the coupled port of the coupling module is connected to the IF port of the up-conversion module,
the output port of the coupling module is connected to the output port of the amplifier,
the RF port of the up-conversion module is connected to the input port of the digital tuning module,
the output port of the digital tuning module is connected to the RF port of the down-conversion module,
the local oscillator is connected to the LO ports of the up- and the down-conversion modules,
the IF port of the down-conversion module is connected to the input port of the low pass filter,
the output port of the low pass filter is connected to the input port of the amplifier.
2. A low frequency active load pull tuner having an input port, an internal port and a test port, comprising
a) a coupling module having input, output and coupled port,
b) an up- and a down-conversion module, each having LO, RF and IF ports,
c) a local oscillator,
d) a digital electronic tuning module having input and output port,
e) a low pass filter having input and output port, and
f) an amplifier having input and output port;
wherein
the input port of the active load pull tuner is connected to the input port of the coupling module,
a signal source is connected to the input port of the active load pull tuner,
the coupled port of the coupling module is connected to the IF port of the up-conversion module,
the output port of the coupling module is connected to the internal port of the active load pull tuner,
the internal port of the active load pull tuner is connected to an input port of a DUT,
the local oscillator is connected to the LO ports of the up- and the down-conversion modules,
the RF port of the up-conversion module is connected to the input port of the digital tuning module,
the output port of the digital tuning module is connected to the RF port of the down-conversion module,
the IF port of the down-conversion module is connected to the input port of the low pass filter,
the output port of the low pass filter is connected to the input port of the amplifier,
the output port of the amplifier is connected to an output port of the DUT.
3. The low frequency active load pull tuner of claim 1 or 2
wherein
the coupling module comprises a directional coupler having input, output and coupling port,
and wherein
the input, output and coupling port of the directional coupler are connected to the associated input, output and coupling port of the coupling module.
4. The low frequency active load pull tuner of claim 1 or 2 ,
wherein
the up-conversion module comprises signal mixer 1 ,
the down-conversion module comprises signal mixer 2 ,
each said signal mixer having RF port, IF port and LO port connected
to the associated RF, IF and LO ports of the corresponding conversion module.
5. The low frequency active load pull tuner of claim 1 or 2 ,
wherein
the digital tuning module comprises
a remotely controlled digital electronic tuner having a test port and an idle port,
a circulator having ports 1 , 2 and 3 ,
and wherein
port 1 of the circulator is connected to the input port of the digital tuning module,
port 2 of the circulator is connected to the test port of the digital electronic tuner,
and port 3 of the circulator is connected to the output port of the digital tuning module,
and wherein
signal flow in the circulator is from port 1 to port 2 , from port 2 to port 3 and from port 3 to port 1 ,
the idle port of the digital electronic tuner is terminated with characteristic impedance.