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Oilseeds are one of the most important determinants of India's agricultural economy, next only to cereals and pulses. The selfsufficiently in oilseed obtained during the early 1990s could not be sustained sufficiently. Despite, being the fourth largest oilseed crop-producing nation in the world, India is also one of the largest importers of vegetable oils. This study appraises t he relationship between price and non-price factors to understand the behaviour of major oilseeds (mustard/rapeseed and groundnut) cultivated in India from 1997-98 to 2019-2020. Supply response is the responsiveness of supply, which can be identified using production response to different determining factors. Mustard/rapeseed and groundnut are the oilseeds that are mainly produced in India. This study specifically attempted to quantify the relationship between oilseed production and different factors, such as annual rainfall, annual temperature, yield, and revenue difference for both crops. The findings suggested that yield and revenue difference of mustard with wheat are the most determining factors for mustard production, whereas annual rainfall, the temperature during the growing season, and revenue difference between groundnut with rice and soyabean are the most significant determinants of groundnut's production response. Crop equivalent productivity further validated that groundnut competed and outperformed the two promising crops (soybean and paddy). The trend analysis (1997-98 to 2019-2020) also indicated that wheat was the dominant crop over mustard from 1997-98 to 2013-14. Afterwards, i.e., from 2014-15 to 2019-20, mustard surpassed wheat productivity (on equivalent terms) and outperformed cereal. [ABSTRACT FROM AUTHOR]

This paper presents a broadband miniaturized Fabry–Perot cavity resonator antenna (CRA) made of novel electromagnetic bandgap (EBG) superstrate as partially reflecting surface (PRS) and reactive impedance surface (RIS) backed rectangular patch antenna. To the best of the authors' knowledge, the proposed EBG exhibits the highest stopband bandwidth (BW) with a bandgap existing between 7.37 and 12.4 GHz (50.9%). Frequency-selective property of the EBG is utilized under plane wave incidence to demonstrate it as PRS superstrate in CRA antenna. The cavity is excited with a rectangular microstrip antenna which is made of two dielectric substrates with an additional RIS layer sandwiched between them. The RIS provides wideband impedance matching of the primary feed antenna. A 7 × 7 array of the EBG superstrate is loaded over the patch antenna having an overall lateral dimension of only 45 × 45 mm2 or 1.62 λ 0 × 1.62 λ 0 where λ 0 is the free space wavelength at the center frequency of 10.8 GHz. The proposed Fabry–Perot CRA (FP-CRA) achieves gain enhancement of 6.59 dB as compared with the reference antenna and has a 10 dB return loss BW of 23.79% from 10.07 to 12.79 GHz. A prototype of the FP-CRA is fabricated and experimentally tested with single and dual layers of EBG superstrate. Measured results show BWs of 21.5 and 24.8% for the two cases with peak realized gain of 12.05 and 14.3 dBi, respectively. Later a four-element antenna array with corporate feeding is designed as the primary feed of the CRA. The simulation result shows a flat gain of >13 dBi with gain variation <1.2 dB over the impedance BW of 13.2%. [ABSTRACT FROM AUTHOR]

This work presents a miniaturized angularly stable frequency selective surface (FSS) on a single layer substrate. Unit cell comprises of convoluted circular rings connected cross dipole and linear arrow headed dipole printed on both sides of the substrate. A closely spaced dual stop band resonances are obtained at 10 and 14.3 GHz with frequency ratio of 1.43. FSS shows a − 10 dB stopband bandwidth (BW) from 7.32 to 11.05 GHz (40.61%) and 12.68 to 15.97 GHz (22.97%) with >30 dB stop band rejection at center frequencies. FSS poses the features of stable performance under change in polarization and angularly stable response up to 60° incident angle. Later the proposed FSS is printed on grounded thick dielectric substrate and it shows broadband reflection type co to cross polarization conversion from 7.2 to 17.32 GHz (82.54%) with polarization conversion ratio >80% and oblique angle stability up to 35°. To the best of authors' knowledge, this is the first time in literature a single unit cell geometry with two different properties, spatial filtering on transmission and polarization conversion on reflection have been designed and analyzed in details. A finite array with size 25 × 25 of the proposed FSS is fabricated and the measured filter response shows a good agreement with simulated performance at normal and oblique incidences. The proposed FSS is used as a reflector of a dual band monopole antenna and the simulation results shows gain improvement of 5.51 and 3.8 dB at the two stopband frequencies. [ABSTRACT FROM AUTHOR]