Wilkinson power divider
Encyclopedia
In the field of microwave
engineering and circuit design, the Wilkinson Power Divider is a specific class of power divider circuit that can achieve isolation between the output ports while maintaining a matched condition on all ports. The Wilkinson design can also be used as a power combiner because it is made up of passive components and hence reciprocal. First published by Ernest J. Wilkinson in 1960, this circuit finds wide use in radio frequency
communication systems utilizing multiple channels since the high degree of isolation between the output ports prevents crosstalk between the individual channels.
for the common case of a 2-way equal-split Wilkinson power divider at the design frequency is given by
Inspection of the S matrix reveals that the network is reciprocal (
), that the terminals are matched (
), that the output terminals are isolated (
=0), and that equal power division is achieved (
). The non-unitary matrix results from the fact that the network is lossy. An ideal Wilkinson divider would yield 
.
Network theorem governs that a divider cannot satisfy all three conditions (being matched, reciprocal and loss-less) at the same time. Wilkinson divider satisfies the first two (matched and reciprocal), and cannot satisfy the last one( being loss-less). Hence, there is some loss occurring in the network.
No loss occurs when the signals at ports 2 and 3 are in phase and have equal magnitude.
The picture below shows a typical output expected from a Wilkinson Power Divider. The
are almost -3dB, and the 
is low near the design frequency.
The picture below demonstrates a very high isolation between output ports (port 2 & 3)
However, some modification can be done to achieve unequal power division at the output ports. By cascading, the input power might be divided to any
-number of outputs.
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
engineering and circuit design, the Wilkinson Power Divider is a specific class of power divider circuit that can achieve isolation between the output ports while maintaining a matched condition on all ports. The Wilkinson design can also be used as a power combiner because it is made up of passive components and hence reciprocal. First published by Ernest J. Wilkinson in 1960, this circuit finds wide use in radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
communication systems utilizing multiple channels since the high degree of isolation between the output ports prevents crosstalk between the individual channels.
Theory
The scattering parametersScattering parameters
Scattering parameters or S-parameters describe the electrical behavior of linear electrical networks when undergoing various steady state stimuli by electrical signals....
for the common case of a 2-way equal-split Wilkinson power divider at the design frequency is given by
Inspection of the S matrix reveals that the network is reciprocal (
), that the terminals are matched (), that the output terminals are isolated (=0), and that equal power division is achieved (). The non-unitary matrix results from the fact that the network is lossy. An ideal Wilkinson divider would yield .Network theorem governs that a divider cannot satisfy all three conditions (being matched, reciprocal and loss-less) at the same time. Wilkinson divider satisfies the first two (matched and reciprocal), and cannot satisfy the last one( being loss-less). Hence, there is some loss occurring in the network.
No loss occurs when the signals at ports 2 and 3 are in phase and have equal magnitude.
The picture below shows a typical output expected from a Wilkinson Power Divider. The
are almost -3dB, and the is low near the design frequency.The picture below demonstrates a very high isolation between output ports (port 2 & 3)
However, some modification can be done to achieve unequal power division at the output ports. By cascading, the input power might be divided to any
-number of outputs.External links
- Online Wilkinson Power Split Calculator
- Online Resistive Power Split Calculator
- Online Coaxial Power Split Calculator
- Wilkinson power divider tutorial with other power divider / combiner pages