Transcript Previous Design Work

Previous Design Work
Zeynep Dilli
[email protected]
Some Design Projects
Optical System Design: A Borescope
(ENEE 408E)
Electronics Circuit Design: AM Radio
System (ENEE 719)
Chip Design: Parasitic Load
Measurements (research work)
Others: An Optical Keyboard, A Pulse Width Modulator,
An External Cavity Laser (undergraduate and previous
research work)
Borescope Design
Borescope: An optical device used to examine
narrow and inaccessible spaces, e.g. inside a gun
barrel or engine cylinder
Specifications: Diameter <25 mm; cost <$1000;
design for a CCD camera as an eyepiece; image
acceptance angle ±25º; periodic relay system to
ensure extensibility.
Design decisions: Lenses w/ diameter <15 mm;
commercial lenses from Melles-Griot; aim for a
focused image to be aligned with focal lens of a
CCD camera.
Borescope Sections
Objective: Achromatic doublets to
create a well-focused image of an
object close to the lens with a
wide angle.
Field Lens: Refocus the rays to
make propagation direction more
axial.
Objective
Field Lens
Relay System: Carry the image
long distances without extra
distortion.
•This is 25 cm long. Adding relay units it can be extended to 34 cm, 43 cm…
AM Radio
Radio receiver/demodulator in the AM range:
– c
between approximately 500 kHz and 1500kHz
– IF
at AM standard, 455 kHz
– LO
then has to vary between 955 kHz and 1955 kHz
AM Radio Frequency Domain
Operation-1
•AM-Modulated signal
•After the LO Mixer---the LO operating
frequency is what we tune; LO-c=IF
where c is the carrier frequency.
•After the IF filter
AM Radio Frequency Domain
Operation-2
•After IF amplification
•After IF Mixer
•After the LPF---Audio-frequency signal.
AM Radio Time Domain Operation
Chip Designs
•Objective: Measure
loading effects of
bonding pads
Effect of Pads—Test Setup
Left: “External” ring oscillator, 11 stages
(two stages are shown). Connection between stages
require going out to the board through bonding pads, wires
and pins.
Both are comprised of minimum-size transistors,
simulated speed for 31 stages: 132 MHz.
Below: Internal ring oscillator, 31 stages, output to
divide-by-64 counter. Direct connection between stages.
Effect of Pads—Results Summary
0.6 m chip, measurements taken by Tektronix oscilloscope
with 1 pF-capacitance active probe on the breadboard
Internal Osc.
External Osc.
One-stage delay
112 MHz (31-stage)
(equivalent to 1.16
GHz for 3 stages)
398 KHz (11-stage)
(equivalent to 1.46
MHz for 3 stages)
~330 ps for internal,
~330 ns for external
devices
Speed ratio: 794.5
Load ratio: ~1000
3-D Integration: “Symmetric” Chip
Chip with
structures that
can be
connected in 3D
and planar
counterparts for
comparison
3-D Connections: “Symmetric” Chip
Same 31-stage planar ring oscillator with counter output
Also 31-stage 3-D ring oscillator with counter output
(On the figure, groups of 5-5-5-5-5-6).
The proper pairs of pads
have to be connected to
each other through
vertical through-chip vias
post-fabrication for the
circle to close.
Simulation results:
Planar: 142 MHz
3-D, six “layer”s: 122 MHz
To counter input
“symmetry” axis