Radial line slot antenna arrays
In some examples, a method for generating a set of slot activation configurations for a holographic radial line slot antenna array comprising multiple slots defining a preconfigured slot pattern, each slot activation configuration defining a beam pattern for a signal to be emitted by the antenna, comprises generating a measure for the mutual coupling between the multiple slots in the presence of a signal to be applied to the antenna, the measure comprising a set of scattering parameters defining a scattering matrix for the antenna, using the measure for the mutual coupling, generating a set of impedance parameters for the array, controlling the resonance of at least one of the multiple slots by regulating a value of capacitance of a variable capacitance device provided across the slot, measuring a value for antenna gain of a beam pattern associated with the value of capacitance, selecting a final value of capacitance resulting in the highest measure of gain for the beam pattern, and selecting a slot activation configuration for the beam pattern on the basis of the selected final value of capacitance.
1 . A method for generating a set of slot activation configurations for a holographic radial line slot antenna array comprising multiple slots defining a preconfigured slot pattern, each slot activation configuration defining a beam pattern for a signal to be emitted by the antenna array, the method comprising:
generating a measure for mutual coupling between the multiple slots in the presence of a signal to be applied to the antenna array, the measure comprising a set of scattering parameters defining a scattering matrix for the antenna array;
using the measure for the mutual coupling, generating a set of impedance parameters for the antenna array;
controlling a resonance of at least one of the multiple slots by regulating a value of capacitance of a variable capacitance device provided across the slot using one of multiple discrete values for capacitive reactance;
measuring a value for antenna gain of a beam pattern associated with the value of capacitance;
selecting a final value of capacitance resulting in the highest measure of gain for the beam pattern; and
selecting a slot activation configuration for the beam pattern on the basis of the selected final value of capacitance.
2 . The method of claim 1 , comprising:
measuring a value for radiated power of the antenna array.
3 . The method of claim 1 , comprising:
measuring a value for power in a direction of peak gain for the antenna array.
4 . The method of claim 1 , comprising:
generating an updated measure for the mutual coupling between the multiple slots in the presence of the value of capacitance.
5 . The method of claim 1 , comprising:
determining the measure for the mutual coupling by calculating respective measures of current flowing through resistive elements logically disposed across ports of the multiple slots.
6 . The method of claim 1 , wherein regulating a value of capacitance of a variable capacitance device comprises adjusting respective values of reactive capacitance for the multiple slots.
7 . The method of claim 1 , comprising:
converting the set of impedance parameters for the antenna array to an updated measure for the mutual coupling between the slots in the presence of the value of capacitance.
8 . The method of claim 7 , comprising:
calculating respective measures for excitations of the multiple slots.
9 . A non-transitory machine-readable storage medium encoded with instructions that when executed by one or more processors cause a process to be carried out for generating a set of slot activation configurations for a holographic radial line slot antenna array, the antenna array comprising multiple slots defining a preconfigured slot pattern, each slot activation configuration defining a beam pattern for a signal to be emitted by the antenna array, the process comprising:
generating an impedance matrix for the antenna array using a set of scattering parameters for the antenna array;
controlling a resonant frequency of at least one of the multiple slots by regulating a value of capacitance of a variable capacitance device provided across the slot using one of multiple discrete values for capacitive reactance, whereby to generate an updated impedance matrix for the antenna array;
calculating respective measures of current around the multiple slots using the updated impedance matrix;
calculating respective measures of voltage across the multiple slots using the measures of current and the impedance matrix;
converting the updated impedance matrix to an updated set of scattering parameters; and
using the updated set of scattering parameters and the measures of voltage, calculating a radiation pattern for the antenna array.
10 . The storage medium of claim 9 , the process comprising:
optimizing the resonant frequency using multiple different combinations of capacitive reactance to minimize power reflected from an input port of the antenna array.
11 . The storage medium of claim 9 , the process comprising:
optimizing the resonant frequency using multiple different combinations of capacitive reactance to minimize power transmitted to an unloaded coaxial port of the antenna array.
12 . The storage medium of claim 9 , the process comprising:
optimizing the resonant frequency using multiple different combinations of capacitive reactance to maximize power radiated in a selected direction.
13 . The storage medium of claim 9 , the process comprising:
generating a set of slot activation configurations, each slot activation configuration defining a capacitive reactance for each of the multiple slots for a given beam pattern for the antenna array.
14 . A non-transitory machine-readable storage medium encoded with instructions that when executed by one or more processors cause a process to be carried out for generating a set of slot activation configurations for a holographic radial line slot antenna array, the antenna array comprising multiple slots defining a preconfigured slot pattern, each slot activation configuration defining a beam pattern for a signal to be emitted by the antenna array, the process comprising:
using a measure for mutual coupling between the multiple slots, generating a set of impedance parameters for the antenna array, the measure for the mutual coupling generated in the presence of a signal applied to the antenna array and comprising a set of scattering parameters defining a scattering matrix for the antenna array;
controlling a resonance of at least one of the multiple slots by regulating a value of capacitance of a variable capacitance device provided across the slot using one of multiple discrete values for capacitive reactance;
measuring a value for antenna gain of a beam pattern associated with the value of capacitance;
selecting a final value of capacitance resulting in the highest measure of gain for the beam pattern; and
selecting a slot activation configuration for the beam pattern on the basis of the selected final value of capacitance.
15 . The storage medium of claim 14 , the process comprising one or both of:
measuring a value for radiated power of the antenna array;
measuring a value for power in a direction of peak gain for the antenna array.
16 . The storage medium of claim 14 , the process comprising:
generating an updated measure for the mutual coupling between the multiple slots in the presence of the value of capacitance.
17 . The storage medium of claim 14 , the process comprising:
converting the set of impedance parameters for the antenna array to an updated measure for the mutual coupling between the slots in the presence of the value of capacitance.
18 . The storage medium of claim 17 , the process comprising:
calculating respective measures for excitations of the multiple slots.