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- __builtin__.object
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- Media
class Media(__builtin__.object) |
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The super-class for all transmission line media.
It provides methods to produce generic network components for any
transmision line medium, such as line, delay_short, etc.
Network Components specific to an instance of the Media super-class
such as cpw_short, microstrip_bend, are implemented within the
Media instances themselves. |
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Methods defined here:
- __init__(self, frequency, propagation_constant, characteristic_impedance, z0=None)
- The Media initializer. This initializer has flexible argument
types, which deserves some explaination.
'propagation_constant', 'characterisitc_impedance' and 'z0' can
all be either static or dynamic. This is achieved by allowing
all those arguments to be either;
functions which take no arguments or
values (numbers or arrays)
in the case where the media's propagation constant may change
after initialization, because you adjusted a parameter, then
passing the propagation_constant as a function can allow
for the properties in this Class to reflect that change.
takes:
frequency: mwavepy.Frequency object
propagation_constant*: propagation constant for the medium.
characteristic_impedance: characteristic impedance of
transmission line medium.
z0**: characteristic impedance for media , IF its different
from the characterisitc impedance of the transmission
line medium (None) [a number].
if z0= None then will set to characterisitc_impedance
returns:
mwavepy.Media Object
*note:
propagation_constant must adhere to the following convention,
positive real(gamma) = attenuation
positive imag(gamma) = forward propagation
**note:
waveguide is an example where you may need this, because
a characteristic impedance is variable but the touchstone's
from most VNA's have z0=1
- capacitor(self, C, **kwargs)
- A lumped capacitor
takes:
C: capacitance, in Farads, [number]
returns:
mwavepy.Network
- delay_load(self, Gamma0, d, unit='m', **kwargs)
- creates a Network for a delayed load transmission line
takes:
Gamma0: reflection coefficient of load (not in dB)
d: the length (see unit argument) [number]
unit: string specifying the units of d. possible options are
'm': meters, physical length in meters (default)
'deg':degrees, electrical length in degrees
'rad':radians, electrical length in radians
**kwargs: key word arguments passed to match(), which is
called initially to create a 'blank' network. the kwarg
'z0' can be used to create a line of a given impedance
returns:
a 1-port Network class, representing a loaded transmission
line of length d
note: this just calls,
line(d,**kwargs) ** load(Gamma0, **kwargs)
- delay_open(self, d, unit='m', **kwargs)
- creates a Network for a delayed open transmission line
takes:
d: the length (see unit argument) [number]
unit: string specifying the units of d. possible options are
'm': meters, physical length in meters (default)
'deg':degrees, electrical length in degrees
'rad':radians, electrical length in radians
**kwargs: key word arguments passed to match(), which is
called initially to create a 'blank' network. the kwarg
'z0' can be used to create a line of a given impedance
returns:
a 1-port Network class, representing a shorted transmission
line of length d
note: this just calls,
line(d,**kwargs) ** open(**kwargs)
- delay_short(self, d, unit='m', **kwargs)
- creates a Network for a delayed short transmission line
takes:
d: the length (see unit argument) [number]
unit: string specifying the units of d. possible options are
'm': meters, physical length in meters (default)
'deg':degrees, electrical length in degrees
'rad':radians, electrical length in radians
**kwargs: key word arguments passed to match(), which is
called initially to create a 'blank' network. the kwarg
'z0' can be used to create a line of a given impedance
returns:
a 1-port Network class, representing a shorted transmission
line of length d
note: this just calls,
line(d,**kwargs) ** short(**kwargs)
- electrical_length(self, d, deg=False)
- calculates the electrical length for a given distance, at
the center frequency.
takes:
d: distance, in meters
deg: is d in deg?[Boolean]
returns:
theta: electrical length in radians or degrees,
depending on value of deg.
- guess_length_of_delay_short(self, aNtwk)
- guess length of physical length of a Delay Short given by aNtwk
takes:
aNtwk: a mwavepy.ntwk type . (note: if this is a measurment
it needs to be normalized to the reference plane)
tline: transmission line class of the medium. needed for the
calculation of propagation constant
- impedance_mismatch(self, z1, z2, **kwargs)
- returns a two-port network for a impedance mis-match
takes:
z1: complex impedance of port 1 [ number, list, or 1D ndarray]
z2: complex impedance of port 2 [ number, list, or 1D ndarray]
**kwargs: passed to mwavepy.Network constructor
returns:
a 2-port network [mwavepy.Network]
note:
if z1 and z2 are arrays or lists, they must be of same length
as the self.frequency.npoints
- inductor(self, L, **kwargs)
- A lumped inductor
takes:
L: inductance in Henrys [number]
returns:
mwavepy.Network
- line(self, d, unit='m', **kwargs)
- creates a Network for a section of matched transmission line
takes:
d: the length (see unit argument) [number]
unit: string specifying the units of d. possible options are
'm': meters, physical length in meters (default)
'deg':degrees, electrical length in degrees
'rad':radians, electrical length in radians
**kwargs: key word arguments passed to match(), which is
called initially to create a 'blank' network. the kwarg
'z0' can be used to create a line of a given impedance
returns:
a 2-port Network class, representing a transmission line of
length d
example:
my_media = mwavepy.Freespace(...)
my_media.line(90, 'deg', z0=50)
- load(self, Gamma0, nports=1, **kwargs)
- creates a Network for a Load termianting a transmission line
takes:
Gamma0: reflection coefficient of load (not in db)
nports: number of ports. creates a short on all ports,
default is 1 [int]
**kwargs: key word arguments passed to match(), which is
called initially to create a 'blank' network
returns:
a n-port Network class, where S = Gamma0*eye(...)
- match(self, nports=1, z0=None, **kwargs)
- creates a Network for a perfect matched transmission line (Gamma0=0)
takes:
nports: number of ports [int]
z0: characterisitc impedance [number of array]. defaults is
None, in which case the Media's z0 is used.
Otherwise this sets the resultant network's z0. See
Network.z0 property for more info
**kwargs: key word arguments passed to Network Constructor
returns:
a n-port Network [mwavepy.Network]
example:
mymatch = wb.match(2,z0 = 50, name='Super Awesome Match')
- open(self, nports=1, **kwargs)
- creates a Network for a 'open' transmission line (Gamma0=1)
takes:
nports: number of ports. creates a short on all ports,
default is 1 [int]
**kwargs: key word arguments passed to match(), which is
called initially to create a 'blank' network
returns:
a n-port Network [mwavepy.Network]
- short(self, nports=1, **kwargs)
- creates a Network for a short transmission line (Gamma0=-1)
takes:
nports: number of ports. creates a short on all ports,
default is 1 [int]
**kwargs: key word arguments passed to match(), which is
called initially to create a 'blank' network
returns:
a n-port Network [mwavepy.Network]
- shunt(self, ntwk, **kwargs)
- returns a shunted ntwk. this creates a 'tee', connects
'ntwk' to port 1, and returns the result
takes:
ntwk: the network to be shunted. [mwavepy.Network]
**kwargs: passed to the tee() function
returns:
a 2-port network [mwavepy.Network]
- shunt_capacitor(self, C, *args, **kwargs)
- a shunt capacitor
takes:
C: capacitance in farads
*args: passed to self.capacitor
**kwargs:passed to self.capacitor
returns:
a 2-port mwavepy.Network
- shunt_delay_load(self, *args, **kwargs)
- a shunted delayed load:
takes:
*args: passed to self.delay_load
**kwargs:passed to self.delay_load
returns:
a 2-port network [mwavepy.Network]
- shunt_delay_open(self, *args, **kwargs)
- a shunted delayed open:
takes:
*args: passed to self.delay_load
**kwargs:passed to self.delay_load
returns:
a 2-port network [mwavepy.Network]
- shunt_delay_short(self, *args, **kwargs)
- a shunted delayed short:
takes:
*args: passed to self.delay_load
**kwargs:passed to self.delay_load
returns:
a 2-port network [mwavepy.Network]
- shunt_inductor(self, L, *args, **kwargs)
- a shunt inductor
takes:
L: inductance in henrys
*args: passed to self.inductor
**kwargs:passed to self.inductor
returns:
a 2-port mwavepy.Network
- splitter(self, nports, **kwargs)
- returns an ideal, lossless n-way splitter.
takes:
nports: number of ports [int]
**kwargs: key word arguments passed to match(), which is
called initially to create a 'blank' network.
returns:
a n-port Network [mwavepy.Network]
- tee(self, **kwargs)
- makes a ideal, lossless tee. (aka three port splitter)
takes:
**kwargs: key word arguments passed to match(), which is
called initially to create a 'blank' network.
returns:
a 3-port Network [mwavepy.Network]
note:
this just calls splitter(3)
- theta_2_d(self, theta, deg=True)
- converts electrical length to physical distance. The electrical
length is given at center frequency of self.frequency
takes:
theta: electrical length, at band center (see deg for unit)
[number]
deg: is theta in degrees? [boolean]
returns:
d: physical distance in meters
- thru(self, **kwargs)
- creates a Network for a thru
takes:
**kwargs: key word arguments passed to match(), which is
called initially to create a 'blank' network
returns:
a 2-port Network class, representing a thru
note:
this just calls line(0)
- white_gaussian_polar(self, phase_dev, mag_dev, n_ports=1, **kwargs)
- creates a complex zero-mean gaussian white-noise signal of given
standard deviations for phase and magnitude
takes:
phase_mag: standard deviation of magnitude
phase_dev: standard deviation of phase
n_ports: number of ports. defualt to 1
**kwargs: passed to Network() initializer
returns:
result: Network type
Data descriptors defined here:
- __dict__
- dictionary for instance variables (if defined)
- __weakref__
- list of weak references to the object (if defined)
- characteristic_impedance
- propagation_constant
- z0
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