Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

BJT Gilbert Mixer

Hetfield

Junior Member level 1
Joined
Aug 31, 2020
Messages
18
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
100
Hello everyone
What should be the bias points for the proper working BJT gilbert cell and what is the relation between the current on the circuit and the circuit specifications. of course i want higher linearity and low noise but what should be the current on the circuit. and i'm having a trouble with the biasing should the Vds of the transistors high or low?
thanks in advance
 

RCinFLA

Advanced Member level 2
Joined
Aug 31, 2010
Messages
569
Helped
185
Reputation
374
Reaction score
182
Trophy points
1,323
Activity points
5,567
A lot depends on what frequency range you want. There may be a trade off of gain vs noise figure.

Look at the ft (current gain vs freq) of devices. Pick a high enough current to get reasonably good current gain.

Make sure devices do not go into saturation. Keep at least a few tenths of a voltage collector voltage over base voltage. You have lower stage and upper switching stage.

Output collectors must have high enough voltage and enough room for AC output swing without going into saturation.
 

BigBoss

Advanced Member level 5
Joined
Nov 17, 2001
Messages
4,842
Helped
1,467
Reputation
2,932
Reaction score
1,314
Trophy points
1,393
Location
Turkey
Activity points
29,208
What Gilbert Cell you talk about ?? Long Tailed Circuit or ?
 

vfone

Advanced Member level 5
Joined
Oct 10, 2001
Messages
5,114
Helped
1,520
Reputation
3,041
Reaction score
1,119
Trophy points
1,393
Activity points
32,351
...What should be the bias points for the proper working BJT gilbert cell...
...i'm having a trouble with the biasing should the Vds of the transistors...
A BJT (Bipolar Junction Transistor) doesn't have Vds (drain to source voltage)
 

Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top