Hi,

To study the fading characteristics of the propagation channel on BAN,

we use the Agilent's PNA-X to measure the S-parameters of the antennas.

The first step is of the measurement is to measure the S-parameters under

narrowband. To make measurement under narrowband propagation. We

select the CW time sweeping mode of the PNA-X.

We are interested to study the stochastic property of the S-matrix. In

other words, we are interested to calculate the first and the second moment

of the entries in S:

E[Sij ] and E[SijSmn]

where i; j; m; n [1; 2; 3; 4]

In order to have an effective observation of the above stochastic process.

However, the PNA-X works in the following way for measuring

the S-matrix over time

- The instrument record S11 over time with the preset sweep points which

is given in the following:

S11(1); S11(2); S11(3) : : : S11(20000)

- The instrument jump to the next S-parameter

As a result, the actual measuring order for the S-parameteres over time is :

S11(1)...S11(n)S12(1)...S12(n)...S44(n) Where n is the number of sweep points.

Please could you help me

Thanks a lot in advance and best regards

To study the fading characteristics of the propagation channel on BAN,

we use the Agilent's PNA-X to measure the S-parameters of the antennas.

The first step is of the measurement is to measure the S-parameters under

narrowband. To make measurement under narrowband propagation. We

select the CW time sweeping mode of the PNA-X.

We are interested to study the stochastic property of the S-matrix. In

other words, we are interested to calculate the first and the second moment

of the entries in S:

E[Sij ] and E[SijSmn]

where i; j; m; n [1; 2; 3; 4]

In order to have an effective observation of the above stochastic process.

**It is desired that the S-matrix can be measured all together over every sweep**However, the PNA-X works in the following way for measuring

the S-matrix over time

- The instrument record S11 over time with the preset sweep points which

is given in the following:

S11(1); S11(2); S11(3) : : : S11(20000)

- The instrument jump to the next S-parameter

As a result, the actual measuring order for the S-parameteres over time is :

S11(1)...S11(n)S12(1)...S12(n)...S44(n) Where n is the number of sweep points.

Please could you help me

**to measue all the Smatrix over every sweep points**?Thanks a lot in advance and best regards

When you have the 4 S-Parameters displayed in a channel or when you have a 2-port calibration turned on, the PNA sweeps all the parameters that have the same source port. This means in your case S11 and S21 are measured at the same time and S22 and S12 are measured in the next sweep. Using your representation, the sweep order is: S11(1)S21(1)...S11(n)S21(n),S22(1)S12(1)...S22(n)S12(n). Unfortunately right now there is no mechanism to allow you to measure all four at exactly the same time since you have two different source ports. However, we are looking at a new model of data acquisition that we call Ping Pong, and in that mode, we will measure the S11/S21 at each trace point, switch the source port and then measure the S22/S12 at the same trace point before proceeding to the next sweep point. There will be a finite time lag between the measurements made with one source port and the measurements made with the next source port. I can't tell right now exactly how long that time will be, but it will be small (micro second time scale). Would such a scheme work for your application?

Regards,