2.4/0.1 = 24 not 240 !!! Bruce > On 06 March 2019 at 17:36 jimlux <[email protected]> wrote: > > > On 3/5/19 3:05 PM, Charles Steinmetz wrote: > > Ho, hum, yet another fantastical claim for magical gain from a > > tiny-for-wavelength antenna. > > > > See the many discussions of same by Kurt N. Sterba over the last several > > decades, among many, many others. > > > > The laws of physics are stubborn things.... > > > these don't violate the theoretical limits.. 100 MHz BW at 2.4 GHz is > pretty high Q (240). > > What I'm interested in is the internal construction - lambda at 2.4 GHz > is 122 mm, and these things are 3x3x4mm. If you tried to dielectrically > load a half wavelength from 61 down to 3mm, that's a factor of 20, which > implies an epsilon of 400. Clearly, that's not what they're doing. > > I'm a bit suspicious about that long feedline in the test fixture. > > > Johansen has lots of these in various frequencies and sizes > https://www.johansontechnology.com/antennas > > Tons of WiFi (2.45 GHz) antennas in all sizes and shapes. > > GPS/GLONASS antennas too > https://www.johansontechnology.com/datasheets/1575AT54A0010/1575AT54A0010.pdf > 12x4mm > > > > > > > > Best regards, > > > > Charles > > > > > > On 3/5/2019 1:48 PM, jimlux wrote: > >> On 3/5/19 9:33 AM, Gregory Beat via time-nuts wrote: > >>> No, this is not an “L-band”, GNSS antenna ... BUT it demonstrates the > >>> shrinking size. > >>> > >>> NEW Molex 206513 Antenna for 2.4 GHz, 3x3x4 mm in size. > >>> Less than $1.00 for quantity 1, both Mouser and Digi-Key now stocking. > >>> https://www.digikey.com/en/product-highlight/m/molex/2-4-ghz-ceramic-antenna > >>> > >>> > >>> > >>> > >>> Molex’s 206513 series is a 2.4 GHz embedded ceramic antenna with high > >>> efficiency over 55% on all frequency bands. This miniature SMT ceramic > >>> component requires a very small (4 mm x 4 mm) keep-out area and is > >>> designed to be mounted directly at the corner of the main device PCB. > >>> It has a frequency range of 2.4 GHz - 2.5 GHz, return loss of <-6 dB, > >>> and peak gain (max) 3.6 dBi. It features an omnidirectional radiation > >>> pattern. > >>> > >> > >> One needs to carefully look at the 55% claim with these kinds of things. > >> Are they including that in the gain, 50% efficiency is a gain hit of > >> 3dB? Peak gain of 3.6dBi (is that circular or linear?) (is that > >> directivity, or gain?). Does the efficiency count the 25% of the power > >> reflected back from the 6dB return loss? > >> > >> https://www.molex.com/pdm_docs/ps/2065130001-PS.pdf is more about > >> packaging > >> > >> https://www.molex.com/pdm_docs/as/2065130001-AS.pdf has the antenna > >> patterns.. > >> > >> > >> > >> Also, what's the axial ratio off boresight... > >> > >> _______________________________________________ > >> time-nuts mailing list -- [email protected] > >> To unsubscribe, go to > >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > >> and follow the instructions there. > > > > > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.
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