Multi-tap transmission line system and methods thereof
Various embodiments are described herein for a multi-tap transmission line. The multi-tap transmission line can comprises: a first end and at least one second end; the transmission line having a corresponding characteristic impedance value (Zc); the first end with a corresponding first end impedance, the first end impedance being same as the characteristic impedance; the at least one second end with a corresponding at least one second end impedance, the corresponding at least one second end impedance being same as the characteristic impedance; at least two tap circuits connected to the transmission line, wherein each tap circuit comprises a tap port and wherein each tap port has a corresponding tap impedance value (Zo). The characteristic impedance value Zc is lower, and in some cases substantially lower, than each tap impedance value Zo.
1. A multi-tap transmission line comprising:
a first end and at least one second end;
the transmission line having a corresponding characteristic impedance value (Zc);
the first end with a corresponding first end impedance, the first end impedance being same as the characteristic impedance;
the at least one second end with a corresponding at least one second end impedance, the corresponding at least one second end impedance being same as the characteristic impedance;
at least two tap circuits connected to the transmission line, wherein each tap circuit comprises a tap port, and wherein each tap port has a corresponding tap impedance value (Zo),
wherein the characteristic impedance value Zc is lower than each tap impedance value Zo, and
wherein, each tap circuit comprises:
a first resistive element corresponding to a first port of the tap circuit, and having a corresponding first resistance value;
a second resistive element corresponding to a second port of the tap circuit, and having a second resistance value;
the first and the second resistive values being substantially equal to a series resistance value (Rs),
a corresponding tap device connected to the corresponding tap port;
a tap resistive element corresponding to the tap port, the tap resistive element having a tap resistance value (Rt),
wherein the first resistance element, the second resistive element and the tap resistive element are connected at a connection point in a T-configuration, and
wherein the characteristic impedance value (Zc) minimizes a worst-case insertion loss (TTLN) between a first tap circuit and a last tap circuit of the at least two tap circuits, the worst-case insertion loss being determined based on a longitudinal insertion loss (LIL) and a transverse insertion loss (TIL) according to:
TTLN
[
dB
]
=
TIL
(
1
)
+
LIL
(
2
)
+
LIL
(
3
)
+
…
+
LIL
(
j
)
+
…
LIL
(
N
-
1
)
+
TIL
(
N
)
;
wherein LIL is a longitudinal insertion loss value determined according to:
LIL
(
j
)
=
20
LOG
10
(
1
-
Zc
/
2
Zo
(
j
)
)
,
wherein Zo(j) is a tap impedance value of a tap port j, j is a range of values indicative of tap index ranging from 2 to (N−1), N representing a total number of tap ports;
wherein TIL is a transverse insertion loss value determined according to:
TIL
(
j
)
=
10
LOG
10
(
Zc
/
4
Zo
(
j
)
)
,
wherein Zo(j) is a tap impedance value of a tap port j, and j is 1 or N.
2. The multi-tap transmission line of claim 1 , wherein the tap devices are selected from the group consisting of an output radiofrequency (RF) transmitter, an input RF receiver, a combined input and output RF transceiver, a radio control (RC) transceiver, a plurality of RF transceivers, a test port of a vector network analyzer VNA, a test port of a time domain reflectometry TDR analyzer, a tap of another multi-tap transmission line, any RF device, and a termination.
3. The multi-tap transmission line of claim 1 , wherein the first end impedance and second end impedance remain matched to the transmission line as the tap devices are connected to the multi-tap transmission line.
4. The multi-tap transmission line of claim 1 , wherein the transmission line comprises a splitter configuration, and the at least one second end comprises two second ends.
5. The multi-tap transmission line of claim 1 , wherein the multi-tap transmission line is implemented as a rigid printed circuited board.
6. The multi-tap transmission line of claim 1 , wherein the multi-tap transmission line is implemented as a flexible printed circuits board.
7. The multi-tap transmission line of claim 1 , wherein the first and second resistive elements have a corresponding series resistance value of approximately 0 ohms.
8. A method of optimizing a multi-tap transmission line, the multi-tap transmission line comprising:
a first end and at least one second end;
the transmission line having a corresponding characteristic impedance value (Zc);
the first end with a corresponding first end impedance, the first end impedance being same as the characteristic impedance;
the at least one second end with a corresponding at least one second end impedance, the corresponding at least one second end impedance being same as the characteristic impedance;
at least two tap circuits connected to the transmission line, wherein each tap circuit comprises a tap port, and wherein each tap port has a corresponding tap impedance value (Zo);
for each tap circuit:
a first resistive element corresponding to a first port of the tap circuit, and having a corresponding first resistance value; and a second resistive element corresponding to a second port of the tap circuit, and having a second resistance value, the first and the second resistive values being substantially equal to a series resistance value (Rs);
a corresponding tap device connected to the corresponding tap port; and a tap resistive element corresponding to the tap port, the tap resistive element having a tap resistance value (Rt), the first resistance element, the second resistive element and the tap resistive element connected at a connection point in a T-configuration;
wherein the method comprises, for each corresponding tap impedance value (Zo), and for a total number of tap ports in the transmission line:
determining an optimal characteristic impedance value (Zc); and
based on the optimal characteristic impedance value (Zc), determining the series resistance value (Rs) and the tap resistance value (Rt) value such that a loss between a first tap circuit and a last tap circuit is minimized, wherein determining the optimal characteristic impedance value (Zc) comprises:
selecting a candidate impedance value, the candidate impedance value being selected from a range of values between 0 and an end impedance value;
for each candidate impedance value:
determining a worst-case insertion loss between the first tap circuit and the last tap circuit based on the candidate impedance value and a tap impedance value corresponding to a tap port, the worst-case insertion loss (TTLN) being determined based on determining a longitudinal insertion loss (LIL) and a transverse insertion loss (TIL) according to:
TTLN
[
dB
]
=
TIL
(
1
)
+
LIL
(
2
)
+
LIL
(
3
)
+
…
+
LIL
(
j
)
+
…
LIL
(
N
-
1
)
+
TIL
(
N
)
;
wherein LIL is a longitudinal insertion loss value determined according to:
LIL
(
j
)
=
20
LOG
10
(
1
-
Zc
/
2
Zo
(
j
)
)
,
wherein j is a range of values indicative of tap index, ranging from 2 to (N−1), N representing the total number of tap ports;
wherein TIL is a transverse insertion loss value determined according to:
TIL
(
j
)
=
10
LOG
10
(
Zc
/
4
Zo
(
j
)
)
,
wherein j is 1 or N, and
determining the optimal characteristic impedance value (Zc) based on the candidate impedance value which minimizes the worst-case insertion loss.
9. The method of claim 8 , wherein the series resistance value (Rs) is determined according to:
R
S
(
j
)
=
Z
c
2
4
Z
O
(
j
)
-
Z
C
wherein Zo(j) is a tap impedance value of a tap port j; j is a range of values indicative of tap index, ranging from 1 to N, N representing the total number of tap ports; and Zc is the optimal characteristic impedance value.
10. The method of claim 9 , wherein the tap resistance value (Rt) is determined according to:
R
t
(
j
)
=
4
(
Z
O
(
j
)
)
2
-
3
Z
C
Z
O
(
j
)
4
Z
O
(
j
)
-
Z
C
wherein Zo(j) is a tap impedance value of a tap port j; j is a range of values indicative of tap index, ranging from 1 to N, N representing the total number of tap ports; and Zc is the optimal characteristic impedance value.
11. The method of claim 8 , further comprising choosing an alternative characteristic impedance value (Zc) from a range between-30% to +30% of the optimal characteristic impedance value.
12. The method of claim 8 , wherein the optimal characteristic impedance value (Zc) is determined by graphical analysis by plotting, as a function of candidate impedance value, a loss function according to:
TTLN
(
Zc
)
=
TIL
(
1
)
+
LIL
(
2
)
+
LIL
(
3
)
+
…
+
LIL
(
j
)
+
…
LIL
(
N
-
1
)
+
TIL
(
N
)
;
and
selecting the optimal characteristic impedance value based on the candidate impedance value corresponding to a minimum value of the loss function, wherein TTLN defines a worst-case insertion loss, LIL defines a longitudinal insertion loss and TIL defines a transverse insertion loss.
13. The method of claim 8 , wherein the first and second resistive elements have a corresponding series resistance value of approximately 0 ohms.
14. A multi-tap transmission line for use in a vehicle, the multi-tap transmission line comprising:
a first end and at least one second end;
the transmission line having a corresponding characteristic impedance value (Zc);
the first end with a corresponding first end impedance, the first end impedance being same as the characteristic impedance;
the at least one second end with a corresponding at least one second end impedance, the corresponding at least one second end impedance being same as the characteristic impedance;
at least two tap circuits connected to the transmission line, wherein each tap circuit comprises a tap port, and wherein each tap port has a corresponding tap impedance value (Zo), and
wherein the characteristic impedance value Zc is lower than the tap impedance value Zo, and
wherein each tap circuit comprises:
a first resistive element corresponding to a first port of the tap circuit, and having a corresponding first resistance value;
a second resistive element corresponding to a second port of the tap circuit, and having a second resistance value;
the first and the second resistive values being substantially equal to a series resistance value (Rs),
a corresponding tap device connected to the corresponding tap port;
a tap resistive element corresponding to the tap port, the tap resistive element having a tap resistance value (Rt),
wherein the first resistance element, the second resistive element and the tap resistive element are connected at a connection point in a T-configuration, and wherein the characteristic impedance value (Zc) minimizes a worst-case insertion loss (TTLN) between a first tap circuit and a last tap circuit of the at least two tap circuits, the worst-case insertion loss being determined based on a longitudinal insertion loss (LIL) and a transverse insertion loss (TIL) according to:
TTLN
[
dB
]
=
TIL
(
1
)
+
LIL
(
2
)
+
LIL
(
3
)
+
…
+
LIL
(
j
)
+
…
LIL
(
N
-
1
)
+
TIL
(
N
)
;
wherein LIL is a longitudinal insertion loss value determined according to:
LIL
(
j
)
=
20
LOG
10
(
1
-
Zc
/
2
Zo
(
j
)
)
,
wherein Zo(j) is a tap impedance value of a tap port i, i is a range of values indicative of tap index ranging from 2 to (N−1), N representing a total number of tap ports;
wherein TIL is a transverse insertion loss value determined according to:
TIL
(
j
)
=
10
LOG
10
(
Zc
/
4
Zo
(
j
)
)
,
wherein Zo(j) is a tap impedance value of a tap port i, and i is 1 or N.
15. The multi-tap transmission line of claim 14 , wherein the vehicle is an automotive vehicle comprising at least 24 tap devices.
16. The multi-tap transmission line of claim 15 , wherein the tap devices are selected from the group consisting of: vehicle sensors, an Engine Control Unit (ECU), a gateway, and an AI node.
17. The multi-tap transmission line of claim 15 , wherein the multi-tap transmission line is constructed as a flex printed circuit board having a self-adhesive tape.
18. The multi-tap transmission line of claim 14 , further comprising a secondary multi-tap transmission line to provide redundancy.
19. The multi-tap transmission line of claim 18 , wherein one or more tap devices switch from the multi-tap transmission line to the secondary multi-tap transmission line during a failure event.
20. The multi-tap transmission line of claim 14 , wherein the vehicle is a remotely operated vehicle (ROV) and wherein the tap devices are selected from the group consisting of: ROV sensors, an ROV Engine Control Unit (ECU), am ROV gateway, and an ROV AI node.
21. The multi-tap transmission line of claim 20 , wherein the multi-tap transmission line is constructed in a branched configuration.
22. The multi-tap transmission line of claim 21 , further comprising a resistive power splitter to branch the multi-tap transmission line into a plurality of transmission lines.
23. A multi-tap transmission line for use with a plurality of processor chips in an interchip configuration, wherein the multi-tap transmission line is external to the plurality of processor chips and coupled to nodes within the plurality of processor chips, the multi-tap transmission line comprising:
a first end and at least one second end;
the transmission line having a corresponding characteristic impedance value (Zc);
the first end with a corresponding first end impedance, the first end impedance being same as the characteristic impedance;
the at least one second end with a corresponding at least one second end impedance, the corresponding at least one second end impedance being same as the characteristic impedance;
at least two tap circuits connected to the transmission line;
each tap circuit comprises a tap port, wherein each tap port has a corresponding tap impedance value (Zo), and
wherein the characteristic impedance value Zc is lower than the tap impedance value Zo,
wherein each tap circuit comprises:
a first resistive element corresponding to a first port of the tap circuit, and having a corresponding first resistance value;
a second resistive element corresponding to a second port of the tap circuit, and having a second resistance value;
the first and the second resistive values being substantially equal to a series resistance value (Rs),
a corresponding tap device connected to the corresponding tap port;
a tap resistive element corresponding to the tap port, the tap resistive element having a tap resistance value (Rt),
wherein the first resistance element, the second resistive element and the tap resistive element are connected at a connection point in a T-configuration, and
wherein the characteristic impedance value (Zc) minimizes a worst-case insertion loss (TTLN) between a first tap circuit and a last tap circuit of the at least two tap circuits, the worst-case insertion loss being determined based on a longitudinal insertion loss (LIL) and a transverse insertion loss (TIL) according to:
TTLN
[
dB
]
=
TIL
(
1
)
+
LIL
(
2
)
+
LIL
(
3
)
+
…
+
LIL
(
j
)
+
…
LIL
(
N
-
1
)
+
TIL
(
N
)
;
wherein LIL is a longitudinal insertion loss value determined according to:
LIL
(
j
)
=
20
LOG
10
(
1
-
Zc
/
2
Zo
(
j
)
)
,
wherein Zo(j) is a tap impedance value of a tap port i, i is a range of values indicative of tap index ranging from 2 to (N−1), N representing a total number of tap ports;
wherein TIL is a transverse insertion loss value determined according to:
TIL
(
j
)
=
10
LOG
10
(
Zc
/
4
Zo
(
j
)
)
,
wherein Zo(j) is a tap impedance value of a tap port i, and j is 1 or N.
24. The multi-tap transmission line of claim 23 , wherein the multi-tap transmission line is implemented as a rigid printed circuited board.
25. The multi-tap transmission line of claim 23 , wherein the multi-tap transmission line is implemented as a flexible printed circuits board.
26. The multi-tap transmission line of claim 23 , wherein the multi-tap transmission line is implemented in at least one of: chip silicon substrates, chiplets and interposers.