1
GATE ECE 1989
MCQ (Single Correct Answer)
+1
-0.3
A logic family has threshold voltage $${V_T}$$= 2V, minimum guaranteed output high voltage $${V_{OH}}$$= 4V, minimum accepted input high voltage $${V_{IH}}$$ = 3V, maximum guaranteed output low voltage $${V_{OL}}$$ = 1V, and maximum accepted input low voltage N $${V_{IL}}$$ =1.5V. Its noise margin is
A
2V
B
1V
C
1.5V
D
0.5V
2
GATE ECE 1989
MCQ (More than One Correct Answer)
+1
-0
Indicate which of the following logic gates can be used to realize all possible combinational Logic functions:
A
OR gates only.
B
NAND gates only.
C
EX-OR gates only.
D
NOR gates only.
3
GATE ECE 1989
Subjective
+10
-0
Design a rectangilar hollow metal waveguide to operate in the X-band such that at an operating free-space wavelength of 3.2 cm
(a) The guide-wavelength for the $$T{E_{{{10}^ - }}}$$ mode is 40% more than the operating free-space wavelength.
(b) The cut-off wavelength for the $$T{M_{{{11}^ - }}}$$ mode is 40% of the cut-off wavelength for the $$T{E_{{{10}^ - }}}$$ mode.
4
GATE ECE 1989
Subjective
+10
-0
Two vertically oriented half wave dipoles are spaced 1.5 wavelengths apart to from an array. Calculate the half power beam widths of the major lobes of the array, in the horizontal plane for the following two cases when the dipoles are fed with

(a) equal and in - phase currents (Broadside array)
(b) equal currents but with a phase difference of 5400 between the two currents (End fire array)