New dielectric ceramics with formula BaTi3Nb4, O„ and Ba6Til4Nbz039 have been prepared and characterized. BaTi3Nba017 was densified to 92% of TD after firing at 1310 oC for 4 h. However, Ba6Ti 1 4Nb2O39 fired under optimized conditions (1260 ` C for 4 h) showed only 85% TD together with secondary phase. The crystal system of both of the compositions is orthorhombic
Jacob,George; Aanandan,C K; Mohanan,P; K G Nair; Sreemoolanathan,H; Sebastian,M T(Microwave and Optical Technology Letters, February 20, 1998)
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Abstract:
A new method for enhancing the 2.1 VSWR impedance
bandwidth of microstrip antennas is presented. Bandwidth enhancement
is achieved by loading the microstrip antenna by a ceramic microwave
dielectric resonator (DR). The validity of this technique has been established
using rectangular and circular radiating geometries. This method
improves the bandwidth of a rectangular microstrip antenna to more
than 10% (= 5 times that of a conventional rectangular microstrip
antenna) with an enhanced gain of I dB
Botha, E C; Odendaal, J W; Geggus, K M(Microwave and Optical Technology Letters, February 20, 1998)
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Abstract:
Compact-range radar backscatter measurements are taken
of aircraft scale models. In addition, computer software is used to predict
the RCS of the aircraft. Synthetic down-range profiles formed from the
two sources of backscatter data are compared and visualized in an
innovative manner. Similar discrimination rates between the two aircraft
are obtained on data from both source
Jacob,George; Aanandan,C K; Mohanan,P; K G Nair(IEEE Journals/ Transactions (USA), 1998)
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Abstract:
A new compact micro strip antenna element is analyzed.
The analysis can accurately predict the resonant frequency,
input impedance, and radiation patterns. The predicted results
are compared with experimental results and excellent agreement
is observed . These antenna elements are more suitable in applications
where limited antenna real estate is available