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- Nov 12, 2018
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Hi Fred,
I am not sure that this is a true statement: "RF signal absorption is directly proportional to conductivity" without some specific definitions, really we are talking about impedance, energy transfer and energy loss to heat. Antennas inherently absorb RF energy [transfer in] and then re-radiate [transfer out], at the same time resistive losses absorb some of it. High conductivity/low resistance elements have higher efficiency transferring energy in and out so yes, they will interact. A 'lossy' element of the same physical dimension will see the same voltage field and will still interact but with a different effective impedance. To claim that it will "interact" more or less [and that 'more' is worse than 'less'] one would need to establish the actual effect [ideally with measured data]. One could easily be making an effective absorber that attenuates the signal more and redistributes the radiation pattern less. Which one is better kind of depends.
This article <https://ieeexplore.ieee.org/document/8261793> suggests that your titanium hardware will 'interact' more over a wider frequency band than a higher conductivity material that will be 'peakier', which is consistent with filter design theory [higher resistance means lower Q and wider bandwidth].
Regardless, the merits of titanium being discussed are relative to carbon steels and stainless steels. All are pretty close together in electrical properties, with stainless edging out the others, making stainless a theoretically better choice [unless it is not].
I would be very interested in any published work you can point me to on the merits of different antenna element materials, as I am still finding very little on the subject.
br/
Tony
I am not sure that this is a true statement: "RF signal absorption is directly proportional to conductivity" without some specific definitions, really we are talking about impedance, energy transfer and energy loss to heat. Antennas inherently absorb RF energy [transfer in] and then re-radiate [transfer out], at the same time resistive losses absorb some of it. High conductivity/low resistance elements have higher efficiency transferring energy in and out so yes, they will interact. A 'lossy' element of the same physical dimension will see the same voltage field and will still interact but with a different effective impedance. To claim that it will "interact" more or less [and that 'more' is worse than 'less'] one would need to establish the actual effect [ideally with measured data]. One could easily be making an effective absorber that attenuates the signal more and redistributes the radiation pattern less. Which one is better kind of depends.
This article <https://ieeexplore.ieee.org/document/8261793> suggests that your titanium hardware will 'interact' more over a wider frequency band than a higher conductivity material that will be 'peakier', which is consistent with filter design theory [higher resistance means lower Q and wider bandwidth].
Regardless, the merits of titanium being discussed are relative to carbon steels and stainless steels. All are pretty close together in electrical properties, with stainless edging out the others, making stainless a theoretically better choice [unless it is not].
I would be very interested in any published work you can point me to on the merits of different antenna element materials, as I am still finding very little on the subject.
br/
Tony