RF FUNDAMENTALS

Presented By

BHUPINDER SINGH

Co-axial transmission line

Characteristic Impedance of Coaxial Line

Phase Shift

Using above, we get

Complex Propagation Constant

Co-axial transmission line

Strip transmission line

Ref: S B Cohn, “Problems in Strip Transmission Lines”

Quasi - TEM Mode

Synthesis of W/h

Effect of Strip thickness

Shielding effect in u-strip line

RULE OF THUMB: b>7*h and a>10*h

Capacitance of Micro-strip line

Capacitance of coupled line

Symmetrical coupled line

Symmetrical coupled line

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Poor coupler directivity, spurious response at 2f0 in parallel coupled line filters

Compensation for unequal phase velocities

S Parameters

For an N-Port Network

Edge Coupled Filter

Edge Coupled Filter

An approximate value for the physical length is obtained from average of even and odd mode velocities, i.e.

Edge Coupled Filter

BW

Broadband Branch Line Coupler

Ref:

Two Port Gain and Stability

Conditional Stability

Unconditional Stability

Gain, NF Circles

Gain: -------------

NF: -------------